研究者データベース

神谷 裕一(カミヤ ユウイチ)
地球環境科学研究院 物質機能科学部門 機能材料化学分野
教授

基本情報

所属

  • 地球環境科学研究院 物質機能科学部門 機能材料化学分野

職名

  • 教授

学位

  • 博士(工学)(名古屋大学)

ホームページURL

科研費研究者番号

  • 10374638

J-Global ID

研究キーワード

  • 触媒化学   Environmental Science   Material Chemistry   Catalysis   

職歴

  • 2015年04月 - 現在 大学院地球環境科学研究院 物質機能科学部門 教授
  • 2007年04月 - 2015年03月 大学院地球環境科学研究院 准教授
  • 2005年03月 - 2007年03月 大学院地球環境科学研究院 助教授
  • 2005年 - 2007年 Associate Professor,Research Faculty of Environmental Earth Science

学歴

  • 1995年04月 - 1997年03月   名古屋大学   大学院   工学研究科応用化学専攻修士課程
  • 1991年04月 - 1995年03月   名古屋大学   工学部   応用化学科

所属学協会

  • ゼオライト学会   触媒学会   日本化学会   石油学会   

研究活動情報

論文

  • Drastic change in selectivity caused by addition of oxygen to the hydrogen stream for the hydrogenation of nitrite in water over a supported platinum catalyst
    Jun Hirayama, Kei-ichiro Yasuda, Sayaka Misu, Ryoichi Otomo, Yuichi Kamiya
    Catalysis Science & Technology 2019年 [査読有り][通常論文]
  • Ryoichi Otomo, Chiaki Yamaguchi, Daiki Iwaisako, Shun Oyamada, Yuichi Kamiya
    ACS Sustainable Chemistry & Engineering 7 3027 - 3033 2019年 [査読有り][通常論文]
  • Ryoichi Otomo, Ryota Osuga, Junko N. Kondo, Yuichi Kamiya, Toshiyuki Yokoi
    Applied Catalysis A: General 575 20 - 24 2019年 [査読有り][通常論文]
  • Shuhei Yasuda, Atsuki Iwakura, Jun Hirata, Mitsuru Kanno, Wataru Ninomiya, Ryoichi Otomo, Yuichi Kamiya
    Catalysis Communications 125 43 - 47 2019年 [査読有り][通常論文]
  • STRAD project for systematic treatments of radioactive liquid wastes generated in nuclear facilities
    Sou Watanabe, Hiromichi Ogi, Yoichi Arai, Haruka Aihara, Yoko Takahatake, Atsuhiro Shibata, Kazunori Nomura, Yuichi Kamiya, Noriko Asanuma, Haruaki Matuura, Toshio Kubota, Noriaki Seko, Tsuyoshi Arai, Tetsuji Moriguchi
    Progress in Nuclear 2019年 [査読有り][通常論文]
  • Ammonia-treated metal oxides as base catalysts for selective isomerization of glucose in water
    Ryoichi Otomo, Momo Fujimoto, Masanori Nagao, Yuichi Kamiya
    Molecular Catalysis 2019年 [査読有り][通常論文]
  • Nuryono Nuryono, Ani Qomariyah, Wontae Kim, Ryoichi Otomo, Bambang Rusdiarso, Yuichi Kamiya
    Molecular Catalysis 2019年 [査読有り][通常論文]
  • Shuhei Yasuda, Jun Hirata, Mitsuru Kanno, Wataru Ninomiya, Ryoichi Otomo, Yuichi Kamiya
    Applied Catalysis A 570 164 - 172 2019年 [査読有り][通常論文]
  • Jun Hirayama, Yuichi Kamiya
    Catalysis Science & Technology 8 4985 - 4993 2018年 [査読有り][通常論文]
  • Ryoichi Otomo, Toshiki Nishitoba, Rota Ogusa, Yusuke Kunitake, Yuichi Kamiya, Takashi Tatsumi, Toshiyuki Yokoi
    Journal of Physical Chemistry C 122 1180 - 1191 2018年 [査読有り][通常論文]
  • Jun Hirayama, Yuichi Kamiya
    JOURNAL OF CATALYSIS 348 306 - 313 2017年04月 [査読有り][通常論文]
     
    A tandem reaction system consisting of a photocatalyst (Pt/TiO2) and a nonphotocatalyst (SnPd/Al2O3) promoted the reduction of NO3- into gaseous products (mainly N-2) under light irradiation (lambda > 300 nm) in the presence of glucose as a hole scavenger. Photocatalytic H-2 evolution (2H(+) + 2(e-) -> H-2) proceeded over Pt/TiO2, and conventional catalytic reduction of NO3- with H-2 (NO3-- + 5/2H(2) -> 1/2N(2) + 2H(2)O + OH-) occurred over SnPd/Al2O3. We optimized the loading amount of Pt on TiO2, the Sn/Pd ratio, the loading amount of SnPd on Al2O3, and the two catalyst dosages. The optimized tandem system gave a high reduction rate of NO3- and a high selectivity for gas (94%) from the photocatalytic reduction of NO3- in water. On the other hand, a typical semiconductor photocatalyst SnPd/TiO2 with an optimized Sn/Pd ratio and an optimized loading amount of SnPd bimetal on TiO2 reduced NO3- about two-thirds as fast as the tandem system and was less selective for gas (70%). The tandem system suppressed the wasted H2 formation, resulting in high light use efficiency for the NO3- reduction (95%), which is defined as the ratio of the number of electrons consumed for NO3- reduction to the total number of electrons consumed for both NO3- reduction and photocatalytic H-2 evolution, though the tandem and SnPd/TiO2 systems consumed about the same total number of electrons. The tandem system has two advantages: (i) the Pt/TiO2 and SnPd/Al2O3 subsystems can be separately designed to give highly efficient photocatalytic and catalytic reactions, respectively; and (ii) the reaction rates of photocatalytic and catalytic reactions can be easily controlled by changing the catalyst dosage in the reactor. Those advantages brought about a high reduction rate for NO3-, high selectivity for gas, and high light use efficiency for NO3- reduction in the photocatalytic reduction of NO3- in water. (C) 2017 Elsevier Inc. All rights reserved.
  • Rika Ochi, Shin-ichiro Noro, Yuichi Kamiya, Kazuya Kubo, Takayoshi Nakamura
    CHEMISTRY-A EUROPEAN JOURNAL 22 31 11042 - 11047 2016年07月 [査読有り][通常論文]
     
    A two-dimensional (2D) layered Mg-II coordination polymer (CP) with a high tolerance for H2O was designed, synthesised, and crystallographically characterised. The synthesis was achieved by the introduction of a flexible 2D layered structure composed of MgII ions and isonicotinate N-oxide ligands. Owing to its high H2O tolerance, the obtained 2D layered structure has the flexibility to repeatedly adsorb a large amount of H2O associated with interlayer expansion and enable the removal of H2O from a H2O/2-propanol mixed vapour. These results indicate that the CP could be an excellent dehydrating agent.
  • Lina Mahardiani, Yuichi Kamiya
    JOURNAL OF THE JAPAN PETROLEUM INSTITUTE 59 1 31 - 34 2016年01月 [査読有り][通常論文]
     
    Catalytic activity of Co3O4 for oxidative decomposition of NH4+ with O-3 in water was greatly enhanced with each reuse of the catalyst under the reaction conditions while maintaining its high selectivity towards gaseous compounds. On the other hand, other metal oxide catalysts showed no or only a little enhancement of the activity. Formation of -NHx, groups on the surface of Co3O4 during the reaction caused the enhancement of the catalytic activity.
  • Ryoichi Otomo, Ryota Kosugi, Yuichi Kamiya, Takashi Tatsumi, Toshiyuki Yokoi
    CATALYSIS SCIENCE & TECHNOLOGY 6 8 2787 - 2795 2016年 [査読有り][通常論文]
     
    Sn-Beta was post-synthetically modified with various cations such as Li+, Na+, K+, Cs+, and NH4+. During the modification process, the ion-exchange of the cations with silanol groups occurred along with a reversible change between "closed" and "open" Sn sites through hydrolysis of the Si-O-Sn bonds. The IR study showed that Sn-Beta had weak Bronsted acid sites, which were passivated by the ion-exchange, in addition to the Lewis acid sites and that surprisingly, basic sites were formed on the modified zeolites. The ion-exchange with a small amount of Li+, Na+ and NH4+ was effective for suppressing side-reactions, leading to an improvement in selectivity to caprolactone in the Baeyer-Villiger oxidation of cyclohexanone with H2O2. The modification of Sn-Beta with such cations also effectively enhanced the catalytic activity in the Baeyer-Villiger oxidation of 2-adamantanone.
  • Hiyoshi, N., Kamiya, Y.
    Chemical Communications 51 49 9975 - 9978 2015年 [査読有り][通常論文]
  • Yukari Iwase, Shogo Sano, Lina Mahardiani, Ryu Abe, Yuichi Kamiya
    JOURNAL OF CATALYSIS 318 34 - 42 2014年10月 [査読有り][通常論文]
     
    Bimodal CsxH4-x[SiW12O40] (Csx-bimodal) with mesopores interconnected with micropores were synthesized from microporous CsxH4-x[SiW12O40 (Csx-micro) with x = 1.0-2.5, which were prepared in advance by titrating an aqueous solution of H-4[SiW12O40] with an aqueous solution of Cs2CO3, followed by treatment in refluxing ethanol to mainly dissolve the H-4[SiW12O40] in the particles. Mesopore size distributions and their pore volumes changed depending on x in Csx-micro. Microporous Cs2.5-micro transformed into bimodal Cs2.5-bimodal with mesopores having average diameters of 3.7 nm and large mesopore volumes. Although Cs2.5-bimodal exhibited only low catalytic activity for the decomposition of isopropyl acetate, post-treatment in H2SO4 enhanced the catalytic activity due to substitution of the Cs' ions on the surface with H+center dot H2SO4-treated Csx-bimodal showed high activity toward transesterification of glyceryl tributyrate with methanol due to its strong acid strength and mesoporosity. (C) 2014 Elsevier Inc. All rights reserved.
  • Sho-ichi Ichikawa, Lina Mahardiani, Yuichi Kamiya
    CATALYSIS TODAY 232 192 - 197 2014年09月 [査読有り][通常論文]
     
    Oxidative decomposition of NH4* (10 mmol L-1) with 03 in water was studied at 333 K over a variety of metal oxide catalysts without pH control of the solution. Although MgO and NiO had the highest catalytic activities, large amounts of undesired NO3- formed due to low selectivity to gaseous products as well as high activity. Co304, which was slightly less active than MgO and NiO, was the best catalyst in terms of activity, selectivity to gaseous products, and dissolution degree among the metal oxide catalysts studied. Over Co304, NH4* was selectively oxidized to N2 with 88% selectivity in water, and the dissolution degree of Co304 was less than 1%. Fe203, Sn02, Mn304, CuO, MgO, and Al203 were less selective to gaseous products or much less active for the reaction. The selectivities to gaseous products were strongly related to the standard enthalpy changes of formation per mol of oxygen atom ( AH'f) of the metal oxides. The metal oxide catalysts with low AH'f, like Co304, showed high selectivity to gaseous products probably due to the low surface density of the active oxygen formed from 03 on the catalysts. Chloride ions (Cl present in the reaction solution significantly accelerated the reaction rate for NH4' decomposition with 03 in the presence of Co304. This was due to the involvement of Cl- in the catalytic cycle. For instance, C10-, which may form by the reaction of Cl- with 03 over Co304, could further oxidize NH4*. 2013 Elsevier B.V. All rights reserved.
  • Jun Hirayama, Yuichi Kamiya
    ACS CATALYSIS 4 7 2207 - 2215 2014年07月 [査読有り][通常論文]
     
    We investigated photocatalytic reduction of NO3- in real groundwater in the presence of the photocatalyst Pt/TiO2 and the nonphotocatalyst SnPd/Al2O3, which were dispersed in the groundwater, under irradiation at lambda > 300 nm, with glucose as a hole scavenger. In this system, photocatalytic H-2 evolution (2H(+) + 2e(-) -> H-2) proceeded over Pt/TiO2, and nonphotocatalytic, that is, conventional catalytic, reduction of NO3- with H-2 (NO3- + 5/2H(2) -> 1/2N(2) 2H(2)O + OH-) occurred over SnPd/Al2O3. NO3- (1.0 mmol dm(-3)) in the groundwater completely and selectively decomposed to N-2 (yield 83%) after 120 h with a 300 W Xe lamp (lambda > 300 nm) over the Pt/TiO2-SnPd/Al2O3 system in combination with photooxidative pretreatment of the groundwater over Pt/TiO2 to decompose organic compounds. The decomposition rate of NO3- in the groundwater was still slower than that in an aqueous NO3- solution even after the pretreatment of the groundwater. The lower photocatalytic performance was due to poisoning of Pt/TiO2 with sulfate and silicate ions and poisoning of SnPd/Al2O3 with polymerized silicate ions. On the other hand, cations, including Na+, K+, Mg2+, and Ca2+, in the groundwater did not affect the photocatalytic and catalytic performances of the system. Sulfate ions adsorbed on the Pt sites on Pt/TiO2, where H-2 evolution occurs, and silicate ions deactivated the oxidation sites on TiO2 by reacting with the surface hydroxyl groups, leading to a decline in the photocatalytic performance of Pt/TiO2.
  • Jun Hirayama, Ryu Abe, Yuichi Kamiya
    APPLIED CATALYSIS B-ENVIRONMENTAL 144 721 - 729 2014年01月 [査読有り][通常論文]
     
    Photocatalytic reduction of nitrate in water in the co-presence of Pt/SrTiO3:Rh and SnPd/Al2O3 under visible light irradiation (lambda > 420 nm) was investigated. This reaction system efficiently and selectively promoted the photocatalytic reduction of nitrate to nitrogen, whereas Pt/SrTiO3:Rh or SnPd/Al2O3 alone showed little activity under the reaction conditions. The selectivity to N-2 was 94% under the optimum reaction conditions, where the amounts of Pt/SrTiO3:Rh and SnPd/Al2O3 loaded in the reaction system were 500 mg and 150 mg, respectively. This reaction system showed a superior nitrate decomposition rate and superior selectivity to nitrogen compared with SrTiO3:Rh directly modified with SnPd bimetal. From analysis of the reaction mechanism, hydrogen formed by photoreduction of water over Pt/SrTiO3:Rh acted as the reductant for a non-photocatalytic nitrate conversion reaction over SnPd/Al2O3. Moreover, the products, including formaldehyde and formic acid, formed by photo-oxidation of methanol over Pt/SrTiO3:Rh acted as reductants for nitrate over SnPd/Al2O3. (C) 2013 Elsevier B.V. All rights reserved.
  • Yu-ki Miura, Hiroyuki Imai, Toshiyuki Yokoi, Takashi Tatsumi, Yuichi Kamiya
    MICROPOROUS AND MESOPOROUS MATERIALS 174 34 - 43 2013年07月 [査読有り][通常論文]
     
    Microporous cesium salts of modified and unmodified tetravalent Keggin-type polyoxometalates, including Cs-4[SiW12O40], Cs-4[PW11O39(Sn-n-C4H9)], and Cs-4[PW11O39(Sn-OH)], were synthesized. The crystalline structures, which had body-centered cubic (bcc) arrangements, the lattice constants, and the pore-size distributions of the three Cs salts were similar, regardless of the presence or absence and types of functional groups introduced. The Cs salts had only micropores and no mesopores. The micropore size distributions were determined from adsorption isotherms of Ar, which showed a sharp peak at 0.59 nm and a shoulder at 0.62 nm. The fractions of the external surface areas to the total surface areas of the Cs salts were less than 6%. It is plausible that the micropores originate from the heteropoly anion defects in the crystallite, which form to avoid mismatches in the Cs+/(heteropoly anion) ratio required for charge balance (=4) and for a bcc structure (=3). The surface of the Cs salt introduced with n-butyl groups was hydrophobic, although the surface density of the n-butyl groups was low. On the other hand, the hydroxyl groups present on the surface of Cs-4[PW11O39(Sn-OH)] had little effect on the adsorption of water, methanol, ethanol, and hexane but a great impact on that for benzene due to the interactions between the -OH groups and the aromatic rings (-OH center dot center dot center dot pi). (C) 2013 Elsevier Inc. All rights reserved.
  • Jun Hirayama, Hirofumi Kondo, Yu-ki Miura, Ryu Abe, Yuichi Kamiya
    CATALYSIS COMMUNICATIONS 20 99 - 102 2012年04月 [査読有り][通常論文]
     
    Photocatalytic reduction of NO3- under UV irradiation in the presence of ethanol was carried out in the presence of semiconductor photocatalyst Pt/TiO2 and supported bimetallic non-photocatalyst Sn-Pd/Al2O3, which were dispersed in water. This system effectively and selectively promoted the photocatalytic reduction of NO3- to N-2, whereas Pt/TiO2 or Sn-Pd/Al2O3 alone showed no or little activity under the reaction conditions. The decomposition rate of NO3- and selectivity to gaseous nitrogen compounds (mainly N-2) for the present photocatalytic system were higher than those for TiO2 photocatalyst directly-modified with Sn-Pd particles. (C) 2012 Elsevier BM. All rights reserved.
  • Yu-ki Miura, Yuichi Kamiya
    CHEMISTRY LETTERS 41 3 331 - 333 2012年03月 [査読有り][通常論文]
     
    Cesium-potassium salt of the lacunary phosphotungstate Cs6.1K0.9[PW11O39), which is a nonporous ionic solid, absorbed only water and methanol, whereas larger alcohols (C >= 2) and hydrocarbons were completely excluded. Cs6.1K0.9[PW11O39] selectively removed water from water-ethanol mixed gas and was reusable by vacuum treatment at room temperature.
  • Ken-ichi Shimizu, Yuichi Kamiya, Kaoru Osaki, Hisao Yoshida, Atsushi Satsuma
    CATALYSIS SCIENCE & TECHNOLOGY 2 4 767 - 772 2012年 [査読有り][通常論文]
     
    The palladium oxidation state of an SiO2-supported palladium catalyst was quantitatively determined by Pd L-3-edge XANES (X-ray absorption near-edge structure) analysis. By changing the time of CO-reduction pre-treatment at 673 K, a series of 5 wt% Pd-loaded SiO2 catalysts (PdOx/2/SiO2) containing different amounts of the Pd metal and PdO phases were prepared, and the average oxidation number (x) was estimated from the number of CO2 molecules formed during the CO-reduction treatment. L-3-edge XANES spectra of these samples and a reference sample (Pd powder) were recorded, and the white line area of the spectra was evaluated. A good linear relationship was confirmed between the white line area intensity and the average oxidation number (x), indicating that the oxidation state of Pd in structurally unknown Pd samples could be quantitatively determined by a simple XANES analysis. To demonstrate the utility of this method in a catalytic study, the effect of the oxidation number (x) on the CO oxidation activity of PdOx/2/SiO2 was also examined, and metallic Pd-0 sites in PdOx/2/SiO2 were shown to be active species.
  • Ken-ichi Shimizu, Tomonori Oda, Yoshinori Sakamoto, Yuichi Kamiya, Hisao Yoshida, Atsushi Satsuma
    APPLIED CATALYSIS B-ENVIRONMENTAL 111 509 - 514 2012年01月 [査読有り][通常論文]
     
    Quantitative determination of average rhodium oxidation state for supported rhodium catalyst was examined by using Rh L-3-edge XANES (X-ray absorption near-edge structure) spectra. A series of Rh-loaded SiO2 catalysts (Rh2Ox/SiO2) containing different amount of Rh metal and Rh2O3 phases were prepared, and the average oxidation number (x) was determined by the amount of CO2 formed during CO reduction treatment as the final step of catalyst preparation. L-3-edge XANES spectra of these samples were recorded, and the white line area intensity of the spectra was evaluated. A good linear relationship was confirmed between the white line area intensity and the average oxidation number (x), indicating that the oxidation state of Rh species in structurally unknown Rh samples could be quantitatively determined by a simple L-3-edge XANES analysis. The effect of the oxidation number (x) on the Rh2O/SiO2-catalysed CO oxidation was discussed, in order to demonstrate a utility of this method in a catalytic study. (C) 2011 Elsevier B.V. All rights reserved.
  • Mitsuru Kanno, Yu-ki Miura, Toshiya Yasukawa, Toshio Hasegawa, Wataru Ninomiya, Ken Ooyachi, Hiroyuki Imai, Takashi Tatsumi, Yuichi Kamiya
    CATALYSIS COMMUNICATIONS 13 1 59 - 62 2011年10月 [査読有り][通常論文]
     
    Gas-phase oxidation of methacrolein to methacrylic acid has been carried out over various unsupported and supported H4PMo11VO40 catalysts. While SiO2-supported H(4)PMo(11)VO(40)showed low selectivity to methacrylic acid, H4PMo11VO40 supported on NH3-modified SiO2, which was prepared by using an impregnation method with acetone as the solvent, exhibited high selectivity (similar to 90%) and high activity for the formation of methacrylic acid. The activity of H4PMo11VO40/NH3-modified SiO(2)was more than five times higher than that of the corresponding unsupported catalysts. (C) 2011 Elsevier B.V. All rights reserved.
  • Jiao Zhang, Mitsuru Kanno, Yi Wang, Hiromi Nishii, Yu-ki Miura, Yuichi Kamiya
    JOURNAL OF PHYSICAL CHEMISTRY C 115 30 14762 - 14769 2011年08月 [査読有り][通常論文]
     
    Changes in surface acidity of H(4)SiW(12)O(40)/SiO(2) in relation to the loading amount were investigated by using temperature-programmed desorption (TPD) of benzonitrile (BN), BN infrared (BN-IR) spectroscopy, and test reactions, including skeletal isomerization of n-butane and double-bond shift of 1-butene. From BN-TPD profiles and BN-IR spectra, H(4)SiW(12)O(40)/SiO(2) had medium strength Bronsted (Mid-B site) and strong Bronsted acid sites (Strong-B site) on its outermost surface, whereas there was no evidence for Lewis acid sites regardless of the loading amount. The number of Strong-B sites correlated with the catalytic activity for the skeletal isomerization of n-butane and was a maximum when the loading amount was 50 wt %. On the other hand, the number of Mid-B sites was a maximum for 30 wt % H(4)SiW(12)O(40)/SiO(2), which had the highest activity for the double-bond shift reaction of 1-butene. Mid-B sites of H(4)SiW(12)O(40)/SiO(2) were present in the starting H(4)SiW(12)O(40), whereas the Strong-B sites formed when H(4)SiW(12)O(40) was supported on SiO(2). There were no Strong-B sites on H(4)SiW(12)O(40)/SiO(2) with low loadings, including 5 and 10 wt %. Thus, it was concluded that the direct interaction of H(4)SiW(12)O(40) with the surface of SiO(2) caused the Strong-B sites to form in the second-layer of H(4)SiW(12)O(40) exposed on the surface.
  • Hiroshi Hinou, Naohiro Saito, Takahiro Maeda, Masao Matsuda, Yuichi Kamiya, Shin-Ichiro Nishimura
    JOURNAL OF CARBOHYDRATE CHEMISTRY 30 7-9 575 - 586 2011年 [査読有り][通常論文]
     
    The simple doping of calcium chloride allowed highly improved yields in the glycosylation promoted by sulfated zirconia (SZ) without calcination. It was revealed by means of per-O-benzylated galactose trichloroacetimidate as a model glycosyl donor that this effect depends greatly on the cationic ion radius of used metal chlorides. Temperature-programmed desorption of ammonia (NH3 TPD) and the pyridine IR method showed clearly that coordination of calcium ion provides the SZ surface with newly formed Lewis acidic sites while the Bronsted acid site disappeared, indicating that the enhanced catalytic potency of SZ is due to the increased Lewis acid sites by doping the optimal calcium ions. The present findings might give insight into the relationship between a catalytic mechanism and superacidity of SZ, which is crucial for the design of novel superacid-based catalysts and environmentally benign glycosylation processes.
  • Yuichi Kamiya, Shogo Sano, Yu-Ki Miura, Yohei Uchida, Yuki Ogawa, Yukari Iwase, Toshio Okuhara
    CHEMISTRY LETTERS 39 8 881 - 883 2010年08月 [査読有り][通常論文]
     
    An acidic Cs salt of H4SiW12O40 (Cs3HSiW12O40), which was prepared by titrating an aqueous solution of H4SiW12O40 with an aqueous solution of Cs2CO3, possessed only micropores and exhibited size-selective catalysis for acid-catalyzed reactions in liquid phase.
  • Jin Zhang, Mitsuru Kanno, Jiao Zhang, Ryuichiro Ohnishi, Kakeru Toriyabe, Hiromi Matsuhashi, Yuichi Kamiya
    JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL 326 1-2 107 - 112 2010年07月 [査読有り][通常論文]
     
    Modification of 15 wt% H(4)SiW(12)O(40)SiO(2) with Na(+) ions was investigated. Na-modified H(4)SiW(12)O(40)/SiO(2) showed higher selectivity for isobutene oligomerization in the preferential oligomerization of isobutene in an equimolar mixture of isobutene and 1-butene than the unmodified one and the selectivity increased with an increase in the Na(+) ion content. The highest selectivity (similar to 97%) was achieved by using Na(3)HSiW(12)O(40)/SiO(2). The activity decreased with an increase in the Na(+) ion content. Unmodified H(4)SiW(12)O(40)/SiO(2) had two kinds of acid sites with different acid strengths (medium and strong acid sites) on the outermost surface as revealed by temperature-programmed desorption of benzonitrile. However, the strong acid sites were eliminated by modification with alkaline metal cations: for example, Na(3)HSiW(12)O(40)/SiO(2) had a negligible amount of strong acid sites. Thus, we concluded that the absence of strong acid sites on the outermost surface is the reason for the high selectivity. Li(3)HSiW(12)O(40)/SiO(2) and K(3)HSiW(12)O(40)/SiO(2) also exhibited high selectivity for isobutene oligomerization with activities comparable to that of Na(3)HSiW(12)O(40)/SiO(2). (C) 2010 Elsevier B.V. All rights reserved.
  • Mitsuru Kanno, Toshiya Yasukawa, Wataru Ninomiya, Ken Ooyachi, Yuichi Kamiya
    JOURNAL OF CATALYSIS 273 1 1 - 8 2010年07月 [査読有り][通常論文]
     
    Catalytic oxidation of methacrolein (MAL) to methacrylic acid (MAA) over SiO(2)-supported H(4)PMo(11)VO(40) with different H(4)PMo(11)VO(40) loadings was investigated. H(4)PMo(11)VO(40)/SiO(2) showed high activity in comparison with unsupported H(4)PMo(11)VO(40), and 3.3 mol% H(4)PMo(11)VO(40)/SiO(2) (50 wt.% H(4)PMo(11)VO(40)) had the highest activity, which was five-times larger than that of unsupported H(4)PMo(11)VO(40) due to high dispersion of H(4)PMo(11)VO(40) on SiO(2), as determined by temperature-programmed desorption of benzonitrile. On the other hand, the supported catalysts were less selective toward the formation of MAA. From X-ray diffraction and Raman spectroscopy, it was determined that H(4)PMo(11)VO(40) decomposed to form MoO(3) on SiO(2) during the catalytic reaction. Since SiO(2)-supported MoO(3) and unsupported MoO(3) had only very low selectivity toward the formation of MAA in the oxidation of MAL, it was concluded that the formation of MoO(3) caused the decrease in the catalytic performance of the supported catalysts. (C) 2010 Elsevier Inc. All rights reserved.
  • Ryuichiro Ohnishi, Takeshi Sugu, Hayato Doi, Yoshinori Sakamoto, Yuichi Kamiya
    JOURNAL OF THE JAPAN PETROLEUM INSTITUTE 52 6 341 - 350 2009年11月 [査読有り][通常論文]
     
    Hydroconversion of methylcyclohexane was conducted over various noble metal-loaded catalysts at 493 K and atmospheric pressure. On the bases of the proposed reaction route and the rate of reaction over Ir/H-beta zeolite, which was the best catalyst examined, we concluded that the low yield of the desired dimethylpentanes (18%) and high yield of undesired methylhexanes (25%) were due to two reasons: (1) formation of ethylcyclopentane with high selectivity at low conversions and (2) higher ring-opening rate of ethylcyclopentane (a precursor of methylhexanes) than that of dimethylcyclopentanes (a precursor of dimethylpentanes). In order to improve the yield of dimethylpentanes, two catalysts for ring contraction from methylcyclohexane to ethyl- or dimethyl-cyclopentanes (Pt-H4SiW12O40/SiO2 or Pt/H-beta) and for ring opening of the produced cyclopentanes (Ir/Al2O3) were used either in one reactor as a physical mixture or in two separate reactors connected in series. When the physical mixture (Pt-H4SiW12O40/SiO2 and Ir/Al2O3) was used, there was only a slight increase in the dimethylpentanes yield (20%) with a large amount of undesired products, such as monobranched heptanes and cracked products. In contrast, when two consecutive reactors packed with Ir/H-beta and lr/Al2O3 were used, the yield of dimethylpentanes increased to 30%, which was nearly two times of that of methylhexanes, at a 65% conversion of methylcyclohexane, while the yield of undesired methylhexanes was about 15%.
  • Toshimitsu Goto, Yoshinori Sakamoto, Yuichi Kamiya
    CHEMISTRY LETTERS 38 7 736 - 737 2009年07月 [査読有り][通常論文]
     
    Cs2.5H0.5PW12O40 fixed on silica encapsulating iron oxide nanoparticles through (3-aminopropyl)triethoxysilane could magnetically be separated from an aqueous solution. The catalyst showed activity for the hydrolysis of ethyl acetate in the presence of excess water and was reusable without significant loss of its inherent activity.
  • Yi Wang, Yoshinori Sakamoto, Yuichi Kamiya
    APPLIED CATALYSIS A-GENERAL 361 1-2 123 - 129 2009年06月 [査読有り][通常論文]
     
    Catalytic reduction of nitrate (NO(3)(-)) in groundwater over a Cu-Pd catalyst supported on active carbon was investigated in a gas-liquid co-current flow system at 298 K. Although Cu-Pd/active carbon, in which the Cu/Pd molar ratio was more than 0.66, showed high activity, high selectivity for the formation of N(2) and N(2)O (98%), and high durability for the reduction of 100 ppm NO(3)(-) in distilled water, the catalytic performance decreased during the reduction of NO(3)(-) in groundwater. The catalyst also irreversibly deactivated during the reaction in groundwater. The organic species in the groundwater caused the decrease in the catalytic performance and the irreversible catalyst deactivation. Ozone-treatment of the groundwater to remove the organic species substantially helped to maintain the catalytic activity and to halt the irreversible deactivation of the catalyst. Chloride ion (Cl(-)) in the groundwater also caused the decrease in the activity and selectivity, but the effects of Cl were reversible. Sulfate ion (SO(4)(2-)) and cations, including Mg(2+), Ca(2+) and K(+), had little or no effect on the catalytic performance of Cu-Pd/active carbon, though they were present in the groundwater sample. More than an allowable level of NH(3) (NH(4)(+)) was formed during the catalytic reduction of NO(3)(-) in the groundwater, but was completely removed by the cation-exchange process using Na-mordenite. (C) 2009 Elsevier B.V. All rights reserved.
  • Hiromi Matsuhashi, Hideo Nakamura, Tatsumi Ishihara, Shinji Iwamoto, Yuichi Kamiya, Junya Kobayashi, Yoshihiro Kubota, Takashi Yamada, Takeshi Matsuda, Koichi Matsushita, Kazuyuki Nakai, Hiroyasu Nishiguchi, Masaru Ogura, Noriyasu Okazaki, Satoshi Sato, Ken-ichi Shimizu, Tetsuya Shishido, Seiji Yamazoe, Tatsuya Takeguchi, Keiichi Tomishige, Hiromi Yamashita, Miki Niwa, Naonobu Katada
    APPLIED CATALYSIS A-GENERAL 360 1 89 - 97 2009年05月 [査読有り][通常論文]
     
    The sulfated zirconia project was carried out in order to obtain a broad understanding of the preparation, characterization, and application of the solid superacids of sulfated zirconia. The sulfated zirconia catalysts were prepared by the equilibrium adsorption method and the ammonium sulfate kneading method using the reference catalysts JRC-ZRO-2, -3, -4, and -5, supplied by the Reference Catalyst Division of the Catalysis Society of Japan. The catalysts were characterized by elemental analysis, NH3TPD, XRD, TG-DTA, CO2-TPD, Raman spectroscopy, and measurements of the surface area, pore size distribution. coverage (by the BAT method), and heat of Ar adsorption. In order to compare the catalytic activities, we used the prepared catalysts in the isomerizations of butane and n-heptane, hydroisomerization of heptane, aldol condensation, acylation, esterification, and cracking of cumene. The sulfated zirconia prepared using JRC-ZRO-2 by the equilibrium adsorption method showed the highest activity and larger surface area. On the other hand, the kneading method provided catalysts with high reproducibility. (C) 2009 Elsevier B.V. All rights reserved.
  • Tomoaki Hamada, Yoshinori Sakamoto, Yasunobu Ooka, Toshio Okuhara, Yuichi Kamiya
    CHEMISTRY LETTERS 38 3 222 - 223 2009年03月 [査読有り][通常論文]
     
    Pd supported on sulfated zirconia with a S/Zr ratio of 0.077 exhibited high activity and high selectivity for the oxidation of ethylene to partially oxidized products, including acetaldehyde and acetic acid, in the vapor phase.
  • Jin Zhang, Ryuichiro Ohnishi, Toshio Okuhara, Yuichi Kamiya
    APPLIED CATALYSIS A-GENERAL 353 1 68 - 73 2009年01月 [査読有り][通常論文]
     
    Preferential oligomerization of isobutene in a mixture of isobutene and 1-butene (molar ratio of 1:1) over H(4)SiW(12)O(40)/SiO(2) was investigated with different loadings of H(4)SiW(12)O(40). The catalytic performance of H(4)SiW(12)O(40)/SiO(2) was compared with those of typical solid acids, such as H-beta, SiO(2)-Al(2)O(3), and SO(4)(2-)/ZrO(2). H(4)SiW(12)O(40)/SiO(2) was superior in activity and selectivity for isobutene oligomerization (defined as the fraction of isobutene converted against the total conversion) compared to other catalysts. The activity was sensitive to the H(4)SiW(12)O(40) loading on SiO(2), reaching a maximum at around 40 wt.%, due to the change in the acid amount of the outermost surface as determined by temperature-programmed desorption of benzonitrile. The selectivity for isobutene oligomerization also changed with the H(4)SiW(12)O(40) loading. The highest selectivity (similar to 95%) was achieved using 10 wt.% H(4)SiW(12)O(40)/SiO(2) at 293 K, due to the absence of strong acid sites on the outermost surface. In the conversion of linear butene (1- and 2-butene), an induction period occurred when 10 wt.% H(4)SiW(12)O(40)/SiO(2) Was used, because linear butene cannot adsorb on the acid sites when isobutene is present in the reaction mixture. (C) 2008 Elsevier B.V. All rights reserved
  • Shin-ichiro Noro, Ryo Tsunashima, Yuichi Kamiya, Kazuhiro Uemura, Hidetoshi Kita, Leroy Cronin, Tomoyuki Akutagawa, Takayoshi Nakamura
    ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 48 46 8703 - 8706 2009年 [査読有り][通常論文]
  • Takashi Kawakami, Yasunobu Ooka, Hideshi Hattori, Wenling Chu, Yuichi Kamiya, Toshio Okuhara
    APPLIED CATALYSIS A-GENERAL 350 1 103 - 110 2008年11月 [査読有り][通常論文]
     
    The selective oxidation of ethene to acetic acid in the vapor phase over solid acid-supported Pd catalyst was investigated to elucidate the reaction mechanism and the roles of Pd and acidic sites in promoting the reaction. Two catalysts, Pd-H4SiW12O40/SiO2 and Pd/WO3-ZrO2, exhibited high catalytic activity. Variations in product distribution with contact time, the requirement for the presence of water vapor for the reaction to occur, and the reactivities of possible reaction intermediates indicated that acetic acid is formed via an acetaldehyde intermediate which is produced in a Wacker-type reaction, while the role of the acid sites is to re-oxidize Pd-0 into Pd2+ in the presence of O-2. It was concluded that catalytic efficiency is dependent on maximization of the interface between metallic Pd and acidic surface by establishing an appropriate ratio of Pd and acidic sites. (C) 2008 Elsevier B.V. All rights reserved.
  • SAKAMOTO Yoshinori, KANNO Mitsuru, OKUHARA Toshio, KAMIYA Yuichi
    Catalysis Letters 125 3-4 392 - 395 2008年10月 [査読有り][通常論文]
     
    Cu-Pd bimetallic clusters with a Cu/Pd atomic ratio of 2 supported on active carbon (AC) ([Cu(2)-Pd](cluster)/AC) selectively hydrogenated nitrate ions in water to harmless compounds, including N(2) and N(2)O (> 99% selectivity), and the formation of NH(3) was suppressed to tolerable levels (<.5 ppm). The activity and selectivity of [Cu(2)-Pd](cluster)/AC were superior to that of conventionally prepared Cu-Pd/AC. [Cu(2)-Pd](cluster)/AC showed stationary conversion and selectivity from the onset of the reaction and remained active for up to 110 h.
  • Yoshinori Sakamoto, Chenkai Wang, Toshio Okuhara, Yuichi Kamiya
    CHEMISTRY LETTERS 37 10 1024 - 1025 2008年10月 [査読有り][通常論文]
     
    Titanium dioxide-supported platinum catalyst, which was pretreated with H-2 at 353 K in a reactor just before the reaction. exhibited extremely high activity toward the oxidation of ammonium ions with nitrite ions into nitrogen in water at 353 K.
  • Yoshimi Yamamoto, Shigeru Hatanaka, Katsuyuki Tsuji, Kazuyuki Tsuneyama, Ryuichiro Ohnishi, Hiroyuki Imai, Yuichi Kamiya, Toshio Okuhara
    APPLIED CATALYSIS A-GENERAL 344 1-2 55 - 60 2008年07月 [査読有り][通常論文]
     
    The direct addition of acetic acid to ethylene to form ethyl acetate over H4SiW12O40/SiO2 using SiO2 with various surface areas and mesopore sizes was studied. H4SiW12O40/SiO2 was superior in activity to conventional solid acids including H3PO4/SiO2, Nafion-SiO2, WO3-ZrO2, and unsupported H4SiW12O40. While the selectivity for ethyl acetate was more than 98% regardless of the catalyst, the activities were significantly different. Maximum activity was obtained when SiO2 having a high surface area and moderate pore size (ave. 6 nm) was utilized. The temperature-programmed desorption of benzonitrile technique and XRD both confirmed that this catalyst had a large amount of acid sites located on the outermost surface due to the high dispersion of H4SiW12O40. In contrast, H4SiW12O40/SiO2, with SiO2 of very small mesopores (3 nm) showed a very low activity, despite having the largest amount of acid sites located on the outermost surfaces. On this catalyst, diffusion of the reactant and product were slow due to the very small-sized mesopores. This limited diffusion rate results in its low activity. (C) 2008 Elsevier B.V. All rights reserved.
  • Yuichi Kamiya, Toshio Okuhara, Makoto Misono, Atsuyuki Miyaji, Katsuyuki Tsuji, Tetsuo Nakajo
    CATALYSIS SURVEYS FROM ASIA 12 2 101 - 113 2008年06月 [査読有り][通常論文]
     
    This article reviews recent research and development of supported heteropolyacid (HPA) catalysts; focusing on the acidic and catalytic properties. First the basic knowledge of solid HPAs is provided briefly to facilitate understanding of heterogeneous catalysis of HPAs. Secondly, the structure as well as the physical and chemical properties of supported HPA catalysts is described. Especially the layer structure of HPA dispersed on the surface of SiO(2) and the changes in the surface acidity with the loading level of HPA are discussed. For this purpose, temperature programmed desorption of benzonitrile devised by Okuhara and Kamiya's group is useful. This method is capable to assess the surface acidity of the supported HPA, which controls the catalytic activity for the reactions proceeding by surface-type catalysis. Then, two new industrial processes developed by Showa Denko K. K. are described; (i) production of ethyl acetate from ethylene and acetic acid and (ii) oxidation of ethylene to acetic acid. Supported HPA catalysts are utilized for both processes, which were recently much improved by finely controlling the catalysts and reaction conditions.
  • Atsushi Satsuma, Hironaka Kanbe, Kannan Srinivasan, Shin-ich Komai, Yuichi Kamiya, Tadashi Hattori
    MICROPOROUS AND MESOPOROUS MATERIALS 110 2-3 528 - 533 2008年04月 [査読有り][通常論文]
     
    Nano-sized interlayer space of lamellar vanadyl benzylphosphate was controlled by water content in starting solution. Depending on the water content, three types of lamellar vanadyl benzylphosphate having basal spacings of 1.4 nm, 1.9 nm and 2.3 nm were obtained. It was suggested that the difference in the concentrations of benzyl and hydroxyl groups in the interlayer leads to the variation of the interlayer space. (C) 2007 Elsevier Inc. All rights reserved.
  • Jin Zhang, Ryuichiro Ohnishi, Yuichi Kamiya, Toshio Okuhara
    JOURNAL OF CATALYSIS 254 2 263 - 271 2008年03月 [査読有り][通常論文]
     
    Water minimized a decrease in conversion for the isomerization of linear butene to isobutene on silica-supported heteropolyacid (H4SiW12O40) catalysts while maintaining high selectivity toward isobutene. The role of water was related to surface acidic properties (number of surface acid sites and acid strength) and characteristics of hydrocarbon deposits (extent of deposits and hydrogen/carbon ratio), as determined by benzonitrile and ammonia temperature-programmed desorption as well as temperature-programmed oxidation of fresh and spent catalysts. It appears that highly unsaturated hydrocarbon deposits consisting of 8-12 carbon units covered surface acid sites, especially strong acid sites, limiting the isomerization reaction. Water in the feed was helpful in preserving the acid sites and decreasing the number of carbon units in the hydrocarbon deposits. Thus, conversion occurred more readily in the presence of water than in the absence of water. (C) 2008 Elsevier Inc. All rights reserved.
  • Hiroyuki Imai, Yuichi Kamiya, Toshio Okuhara
    Res. Chem. Intermed 34 8-9 669 - 677 2008年 [査読有り][通常論文]
     
    The exfoliation-reduction of VOPO(4) center dot 2H(2)O in 1-butanol or iso-butanol alone, and ill a 1-butanol/ethanol or iso-butanol/ethanol mixture, were conducted. Although all precursors were composed of a lamellar compound with intercalated alcohol molecules, VOHPO(4) center dot 0.5H(2)O was formed when the exfoliation-reduction process was carried out in the mixed alcohol. All precursors transformed to a single phase of (VO)(2)P(2)O(7) under the reaction conditions for n-butane oxidation, but the crystallinity Of (VO)(2)P(2)O(7) was different. The catalyst synthesized in iso-butanol/ethanol was well crystalline (VO)(2)P(2)O(7), and exhibited higher selectivity to maleic anhydride than that synthesized in iso-butanol alone for the n-butane oxidation.
  • Kannan Srinivasan, Hironaka Kanbe, Takuya Ohkura, Shin-Ichi Komav, Yuichi Kamiya, Tadashi Hattori, Atsushi Satsuma
    RESEARCH ON CHEMICAL INTERMEDIATES 34 5-7 455 - 465 2008年 [査読有り][通常論文]
     
    A novel approach for the preparation of promoted vanadyl pyrophosphate in well-defined structure was examined. Lamellar vanadyl benzylphosphate (LVBP) was used as a host material and iron acetylacetonate as a guest. It was found that iron acetylacetonate was successfully inserted into the interlayer of LVBP by heating of LVBP and iron acetylacetonate in toluene solution. Calcination of this intercalated material resulted in a well-crystallized vanadyl pyrophosphate phase with uniform dispersion of Fe in bulk and surface. The obtained Fe-promoted, vanadyl pyrophosphate showed an enhancement in the activity for selective oxidation-of n-butane, especially at high temperature and long contact time.
  • Hiroyuki Imai, Yuichi Kamiya, Toshio Okuhara
    Journal of Catalysis 255 55 - 60 2008年 [査読有り][通常論文]
  • Yun Hin Taufiq-Yap, Chee Keong Goh, Yuichi Kamiya
    REACTION KINETICS AND CATALYSIS LETTERS 92 2 275 - 284 2007年12月 [査読有り][通常論文]
     
    The addition of 1% Mn promoter to vanadium phosphate catalyst led to doubling of the specific surface area from 20.3 (unpromoted) to 39.4 m(2) g(1). The XRD pattern of the Mn-promoted catalyst gave only the characteristics of the (VO)(2)P2O7 phase, indicating that the Mn was incorporated into the crystal lattice of the catalyst. The Mn-promoted catalyst was also twice as active in removing the total amount of oxygen. However, since the only oxygen species related to V4+ being removed and no oxygen species associated with V5+ was observed, the n-butane conversion was not much improved as compared to the unpromoted counterpart. A necessary amount and distribution of the V5+ phase in a well crystalline V4+ phase is essential in order to enhance the catalytic performance in the mild oxidation of n-butane to maleic anhydride.
  • Atsuyuki Miyaji, Tomoaki Hamada, Yuichi Kamiya, Tetsuo Nakajo, Toshio Okuhara
    CATALYSIS LETTERS 119 3-4 252 - 256 2007年12月 [査読有り][通常論文]
     
    The role of Te in Pd-Te-H4SiW12O40/SiO2, a highly active and selective catalyst for direct oxidation of ethylene to acetic acid, was investigated. Kinetic studies of ethylene oxidation over Pd-H4SiW12O40/SiO2 and Te-promoted Pd-H4SiW12O40/SiO2 demonstrated that doping with Te enhanced the rate of reaction of ethylene to acetaldehyde but reduced direct formation of CO2 from ethylene. In contrast, the successive reaction of acetaldehyde to acetic acid was not influenced to a significant extent by the addition of Te.
  • IMAI Hiroyuki, KAMIYA Yuichi, OKUHARA Toshio
    Journal of Catalysis 251 1 195 - 203 2007年10月 [査読有り][通常論文]
     
    Intercalation, exfoliation, and reduction of VOPO4 center dot 2H(2)O were conducted in 2-butanol alone and in a mixed-alcohol solvent (2-butanol and ethanol). Whereas both processes produced crystallites of pure VOHPO4 center dot 0.5H(2)O, much smaller and thinner crystallites (average size, 340 x 35 nm) were formed in the mixed alcohol compared with 2-butanol alone (average size 950 x 200 nm). The small, thin crystallites of precursor VOHPO4 center dot 0.5H(2)O could be transformed into sharply angular nanosized crystallites (60 nm long and 31 nm thick) of highly crystalline (VO)(2)P2O7, without mesopores. When used as a catalyst, this compound exhibited higher activity and selectivity to maleic anhydride (75% at 80% conversion) for selective oxidation of n-butane compared with that derived from the precursor prepared in 2-butanol alone. The high activity of the nanosized crystallites of (VO)(2)P2O7 is attributed to their large surface area (40 m(2) 9(-1)), which is due to their smaller dimensions, and their high selectivity may be attributed to the lack of mesopores as well as their highly crystalline state. (c) 2007 Elsevier Inc. All rights reserved.
  • Takako Mochida, ryuichiro Ohnishi, Naoto Horita, Yuichi Kamiya, Toshio Okuhara
    Micrporous and Mesoporoous Materials 101 1-2 176 - 183 2007年04月 [査読有り][通常論文]
     
    Acid catalyzed hydration of alpha-pinene in the presence of water was conducted over MFI, BEA, MOR and FAU type zeolites with various SiO2/AI(2)O(3) molar ratios and over many other catalysts. Except for MFI, the catalytic activity of all zeolites increased and, then, fell down with increasing SiO2/AI(2)O(3) ratio. Analysis of water adsorption isotherm and NH3-TPD revealed explicitly that, at high Al content, the crowded water molecules on an acid site inhibit the adsorption of alpha-pinene while, at low Al content, only a small number of water are competing with alpha-pinene to adsorb on an active site. The catalytic activity per acid site of all zeolites increased monotonously with increasing hydrophobicity. (c) 2006 Elsevier Inc. All rights reserved.
  • KAMIYA Yuichi, KAMIYA Yuichi, OOKA Yasunobu, OBARA Chisato, OHNISHI Ryuichiro, FUJITA Toshio, KURATA Youhei, TSUJI Katsuyuki, NAKAJYO Tetsuo, OKUHARA Toshio, OKUHARA Toshio
    Journal of Molecular catalysis A 262 1-2 77 - 85 2007年02月 [査読有り][通常論文]
     
    Friedel-Crafts-type reaction of p-xylene with gamma-butyrolactone or vinylacetic acid over H4SiW12O40 supported on SiO2 have been investigated with different loadings of H4SiW12O40. The catalytic performance of H4SiW12O40/SiO2 have been compared with those of typical solid acid catalysts such as zeolites, ion-exchanged resins, and binary oxides. H4SiW12O40 supported on SiO2 was superior in activity and selectivity to 5,8-dimethyl-alpha-tetralone compared to other catalysts for the reaction between p-xylene and gamma-butyrolactone. SiO2-supported H4SiW12O40 also was efficient for the formation of 3,4,7-tetramethyl-alpha-indanone from p-xylene and vinylacetic acid. The formation of 5,8-dimethyl-a-tetralone is extremely sensitive to the load of H4SiW12O40 on SiO2, reaching a maximum at approximately 30 wt%, due to the change in the acid amount of the outermost surface as determined by benzonitrile-temperature programmed desorption. By analogy with reaction between 1,3,5-trimethylbenzene and gamma-butyrolactone, the reaction pathway involves initial alkylation of p-xylene with gamma-butyrolactone, followed by intramolecular acylation to 5,8-dimethyl-alpha-tetralone, which was supported by quantum calculations of gamma-butyrolactone and protonated gamma-butyrolactone. (c) 2006 Elsevier B.V. All rights reserved.
  • Kei Inumaru, Toru Ishihara, Yuichi Kamiya, Toshio Okuhara, Shoji Yamanaka
    ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 46 40 7625 - 7628 2007年 [査読有り][通常論文]
  • Promotional effect of Te for direct oxidation of ethylene over Pd-H4SiW12O40/SiO2
    Atsuyuki Miyaji, Yuichi Kamiya, Toshio Okuhara, Tetsuo Nakajo
    Studies in Surface Science and Catalysis 172 557 - 558 2007年 [査読有り][通常論文]
  • Cs2.5H0.5PW12O40-SiO2 composite as an excellent water-tolerant solid acid
    Yuichi Kamiya, Naoto Horita, Masaaki Kitakawa, Youhei Uchida, Toshio Okuhara
    Studies in Surface Science and Catalysis 172 421 - 424 2007年 [査読有り][通常論文]
  • Yi Wang, Tomohiro Kasuga, Ikkou Mikami, Yuichi Kamiya, Toshio Okuhara
    Chemistry Letters 36 8 994 - 995 2007年 [査読有り][通常論文]
  • Yi Wang, Yuichi Kmiya, Toshio Okuhara
    WATER RESEARCH 41 2 269 - 276 2007年01月 [査読有り][通常論文]
     
    Removal of low-concentration ammonia (2-10 ppm) in water by ion exchange with Na-form zeolites was investigated using a flow system at 278-333 K. Results indicated that Na-mordenite was the most efficient cation-exchanger (compared with Na-ferrierite, Na-ZSM-5, Na-beta, and Na-Y, as well as the K- and H-form mordenite) for the removal of low-concentration ammonia. The ammonia uptake and the ion-exchange level achieved using mordenite with NH4+ for removal of 10 ppm ammonia at 333 K were 1.21 mmol g(-1) and 79.1%, respectively The high efficiency of Na-mordenite for removal of low-concentration ammonia in water is due to the strong acidity of the corresponding H-form mordenite as demonstrated by ammonia temperature-programmed desorption. Ammonia uptake on the Na-mordenite was minimally influenced by operating temperature in the range of 278-333 K. The coexistent K+ and Na+ in water had little influence on ammonia uptake of the Na-mordenite. In contrast, coexistent Ca2+ and Mg2+ significantly lowered the efficiency of the Na-mordenite for ammonia removal. (c) 2006 Elsevier Ltd. All rights reserved.
  • HORITA Naoto, KAMIYA Yuichi, OKUHARA Toshio
    Chemistry Letters 35 12 1346 - 1347 2006年12月 [査読有り][通常論文]
     
    Cs2.5H0.5PW12O40-SiO2 composite combined with (3-aminopropyl)triethoxysilane exhibited greater activity and selectivity for hydration of alpha-pinene at 333 K in a triphasic system (alpha-pinene/water/solid acid) compared to previously reported water-tolerant catalysts such as zeolites, polymer-resins (Amberlyst 15 and Nation-H), oxides, and liquid acids such as H3PW12O40 and H2SO4. The selectivity toward alcohols, including mono- and dialcohols, was approximately 80% over Cs2.5H0.5PW12O40-SiO2 composite.
  • Yuichi Kamiya, Naonori Ryumon, Hiroyuki Imai, Toshio Okuhara
    CATALYSIS LETTERS 111 3-4 159 - 163 2006年11月 [査読有り][通常論文]
     
    Exfoliation-reduction of VOPO4 center dot 2H(2)O in a mixed alcohol consisting of 2-butanol and ethanol, followed by the thermal treatment in the presence of n-butane, O-2, and He at 663 K for 300 h, produces novel nano-sized crystallites (similar to 50 nm) of (VO)(2)P2O7. The nano-sized (VO)(2)P2O7 crystallites exhibit a high selectivity to maleic anhydride (similar to 84%) for the selective oxidation of n-butane.
  • SUGII Takeshi, KAMIYA Yuichi, KAMIYA Yuichi, OKUHARA Toshio, OKUHARA Toshio
    Applied Catalysis A 312 45 - 51 2006年09月 [査読有り][通常論文]
     
    We studied the conversion of methylcyclohexane into dimethylpentanes in the presence of hydrogen, catalyzed by It supported on H-beta zeolites with different Si/Al ratios. Ir/H-beta catalysts with a high Si/Al ratio (Si/Al = 75 or 150) showed activity in promoting both ring-contraction (from six-membered to five-membered rings) on the acidic sites of H-beta and ring-opening on Ir metal sites, resulting in high activity and selectivity toward dimethylpentanes. In contrast, Ir/H-beta catalysts with a low Si/Al ratio were less active in ring-opening on the Ir metal sites, which resulted in the high selectivity for dimethylcyclopentanes. In the conversions of methylcyclohexane, 2-methylhexane, and 2,4-dimethylpentane, the dependence of the conversion rate on W/F values demonstrated that, for the highly active and selective Ir/H-beta catalyst with Si/Al = 75, methylcyclohexane was first transformed into dimethylcyclopentanes on the acidic sites, followed by ring-opening on the Ir sites to form dimethylpentanes and methylhexanes. The skeletal isomerization of methylhexanes into dimethylpentanes over this catalyst was very slow under the reaction conditions studied. (C) 2006 Elsevier B.V. All rights reserved.
  • Takeshi Sugii, Ryuichiro Ohnishi, Jin Zhang, Atsuyuki Miyaji, Yuichi Kamiya, Toshio Okuhara
    CATALYSIS TODAY 116 2 179 - 183 2006年08月 [査読有り][通常論文]
     
    Difficulty in measuring acidic characters of heteropolyacid due to absorption of common bases such as ammonia and pyridine was circumvented using benzonitrile as an adsorbate. Acidity-attenuated and Pd-promoted heteropolyacid catalysts catalyzed n-heptane skeletal isomerization with high activity and high selectivity to branched heptanes, which are useful as clean high-octane fuels. Acidic characters measured by benzonitrile-TPD were well correlated with the catalytic performances. (C) 2006 Elsevier B.V. All rights reserved.
  • Y Sakamoto, Y Kamiya, T Okuhara
    JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL 250 1-2 80 - 86 2006年05月 [査読有り][通常論文]
     
    Hydrogenation of nitrate (200 ppm) in water with H-2 over Cu-Pd clusters supported on active carbon (AC) was investigated at 333 K using a gas-liquid co-current flow system. Two types of Cu-Pd bimetallic clusters, stabilized with either poly(vinylpyrrolidone) (PVP) or sodium citrate (SC), revealed that the catalysts possessed similar activity (per unit weight of Pd) and high selectivity toward nitrite when pH was 10.5 at the outlet of the reactor. The high selectivity toward nitrite on PVP-stabilized cluster/AC was minimally influenced by the atomic ratio of Cu/Pd (=0.5-4.0); activity was maximal at a ratio of 1:1. Increasing pH to 12.4 by addition of NaOH enhanced the selectivity toward nitrite to 93% over SC-stabilized Co-0.63-Pd cluster/AC, but caused a decrease in the reaction rate. Over Cu-0.63-Pd cluster/AC, hydrogenation of nitrite as an intermediate occurred much more slowly than that of nitrate at pH 10.5, suggesting that high selectivity toward nitrite is attained by OH- inhibiting adsorption of nitrite. XRD and STEM gave the size of the Cu-0.63-Pd cluster on AC as 4 nm; the structure of the cluster remained almost unchanged during the reaction. The activity and selectivity of the Cu-0.63-Pd cluster/AC was superior to those of the Cu-0.63-Pd cluster on oxides such as TiO2, Al2O3, and ZrO2. In addition, the Cu-0.63-Pd cluster/AC was more active and selective than conventionally prepared Cu-0.63-Pd/AC, indicating that the Cu-Pd cluster is an excellent precursor for selective catalysts in the hydrogenation of nitrate to nitrite. (c) 2006 Elsevier B.V. All rights reserved.
  • Promotional effect of bismuth in the Bi-Promoted (VO)2P2O7 catalysts on the selective Oxidation of n-butane to maleic anhydride.
    Yun Hin Taufiq-Yap, Yuichi Kamiya, K.P. Tan
    Journal of Natural Gas Chemistry 15 297 - 302 2006年 [査読有り][通常論文]
  • RYUMON Naonori, IMAI Hiroyuki, KAMIYA Yuichi, OKUHARA Toshio
    Applied Catalysis A: Chemical 297 1 73 - 80 2006年01月 [査読有り][通常論文]
     
    The transformation of VOHPO(4)(.)0.5H(2)O to (VO)(2)P2O7 has been studied in the absence and presence of water vapor (0-40 vol%) using small (340 urn x 40 nm) and large (10,000 nm x 410 nm) VOHPO(4)(.)0.5H(2)O crystallites. The small VOHPO(4)(.)0.5H(2)O crystallites were transformed into a single-phase of well-crystallized (VO)(2)P2O7 within 5 h under a reactant gas (0.9% n-butane, 10% O-2 and He(balance)) containing 40% water vapor, whereas the transformation took more than 100 h in reactant gas without water vapor. In the large-sized VOHPO(4)(.)0.5H(2)O crystallites, (VO)(2)P2O7 was the main phase formed in the presence of reactant gas containing 40% water vapor, whereas alpha(II)-VOPO4 was the main product in the absence of water vapor. It was found that, under the reaction conditions, water vapor accelerated two processes in the transformation of VOHPO(4)(.)0.5H(2)O to (VO)(2)P2O7; the crystallization of the amorphous VP phase containing V4+ and V5+ to (VO)(2)P2O7 and delta-VOPO4, and the transformation of delta-VOPO4 to (VO)(2)P(2)O7, On the other hand, water vapor inhibited the topotactic transformation of VOHPO(4)(.)0.5H(2)O to (VO)(2)P2O7. The two processes accelerated by water vapor resulted in the rapid transformation of VOHPO(4)(.)0.5H(2)O to (VO)(2)P2O7 under the reactant gas. The catalyst obtained in the presence of water vapor gave stationary conversion and selectivity for MA from immediately after the beginning of the reaction. This catalyst showed a high selectivity for MA in comparison to the catalyst transformed in the absence of water vapor. Furthermore, over the catalyst formed in the absence of water vapor, it took more than 100 h to reach stationary conversion and selectivity. (c) 2005 Elsevier B.V. All rights reserved.
  • N Horita, M Yoshimune, Y Kamiya, T Okuhara
    CHEMISTRY LETTERS 34 10 1376 - 1377 2005年10月 [査読有り][通常論文]
     
    Unlike Cs2.5H0.5PW12O40, Cs2.5H0.5PW12O40-SiO2 composites combined using (3-aminopropyl)triethoxysilane are entirely insoluble and well sedimentable in reaction mixtures that contain a large excess of water. The catalytic activities for the hydration of olefin and hydrolysis of ester in the presence of excess water were comparable to those Of Cs2.5H0.5PW12O40 and were much higher than those of typical water-tolerant solid acids, such as H-ZSM-5 and Nb2O5.
  • Y Kamiya, N Yamamoto, H Imai, S Komai, T Okuhara
    MICROPOROUS AND MESOPOROUS MATERIALS 81 1-3 49 - 57 2005年06月 [査読有り][通常論文]
     
    Hexagonal- and lamellar-meso structured vanadium phosphorus oxides were synthesized by assembling exfoliated VOPO4 sheets using cationic surfactants (dodecyl-, tetradecyl-, hexadecyl-, and octadecyltrimethylammonium bromide, CTAB). The products were characterized using X-ray diffraction, SEM, TEM, IR spectroscopy, elemental analysis, and TG/DTA. When a suspension of VOPO4 center dot 2H(2)O crystallites in 2-propanol was thermally treated, 2-propanol intercalated between layers of VOPO4 center dot 2H(2)O, followed by exfoliation of the layers. C(n)TAB was added to the alcoholic solution at 343 K. Treatment of the solution at 343 K for 10 min, followed by evaporation of 2-propanol, which resulted in the formation of hexagonal- and lamellar-phases at C(n)TAB/VOPO4 molar ratios of 0.5, and 1.0, respectively, with chemical formulae of [C16H33N(CH3)(3)Br](0.5)(VOPO4)-0.4H(2)O and [C16H33N(CH3)(3)Br](1.0)(VOPO4), respectively. The unit cell constants of hexagonal- and lamellar-phases from C(16)TAB were a = 3.86 nm and c = 3.87 nm, respectively, and increased with carbon number of the primary chain of C,TAB. In the lamellar phases, the surfactant was incorporated as a double layer at an angle of approximately 27 degrees and its wall consisted of two VOPO4 sheets. (c) 2005 Elsevier Inc. All rights reserved.
  • WL Chu, Y Ooka, Y Kamiya, T Okuhara
    CATALYSIS LETTERS 101 3-4 225 - 228 2005年06月 [査読有り][通常論文]
     
    Pd-supported on WO3-ZrO2 (W/Zr atomic ratio=0.2) calcined at 1073 K was found to be highly active and selective for gas-phase oxidation of ethylene to acetic acid in the presence of water at 423 K and 0.6 MPa. Contact time dependence demonstrated that acetic acid is formed via acetaldehyde formed by a Wacker-type reaction, not through ethanol by hydration of ethylene.
  • WL Chu, Y Ooka, Y Kamiya, T Okuhara, H Hattori
    CHEMISTRY LETTERS 34 5 642 - 643 2005年05月 [査読有り][通常論文]
     
    Pd supported on WO3-ZrO2 calcined at temperatures of 973-1073 K exhibits a high activity and selectivity for the oxidation of ethylene to acetic acid in the vapor phase. The space time yield (STY) per unit volume of catalyst is higher for Pd/WO3ZrO2 than for Pd/H4SiW12O40-SiO2, the best catalyst reported to date.
  • YH Taufiq-Yap, CK Goh, KC Waugh, Y Kamiya
    REACTION KINETICS AND CATALYSIS LETTERS 84 2 271 - 278 2005年 [査読有り][通常論文]
     
    1% of Fe-doped and undoped vanadyl pyrophosphate catalysts were prepared via dihydrate method. The catalysts have been characterised by XRD, ICP, BET and SEM. The undoped catalyst was found to be more active and selective (77.6% selectivity at about 60% conversion at 703 K).
  • SAKAMOTO Yoshinori, NAKAMURA Kyosuke, KUSHIBIKI Rie, KAMIYA Yuichi, OKUHARA Toshio
    Chemistry Letters 34 11 1510 - 1511 2005年 [査読有り][通常論文]
  • Bunshi Fugetsu, Wenhai Han, Noriaki Endo, Yuichi Kamiya, Toshio Okuhara
    Chemistry Letters 34 9 1218 - 1219 2005年 [査読有り][通常論文]
  • Y Sakamoto, K Nakata, Y Kamiya, T Okuhara
    CHEMISTRY LETTERS 33 7 908 - 909 2004年07月 [査読有り][通常論文]
     
    Cu-Pd/AC catalysts that are derived from Cu-Pd clusters were shown to possess high activity for the reduction of nitrate to nitrite, but were inactive for the reduction of nitrite. In contrast, the Pd/AC catalyst was inactive for the reduction of nitrate, whereas conventional Cu-Pd/AC afforded various products, including nitrite, nitrogen, and ammonia.
  • WL Chu, T Echizen, Y Kamiya, T Okuhara
    APPLIED CATALYSIS A-GENERAL 259 2 199 - 205 2004年03月 [査読有り][通常論文]
     
    Hydration of ethene over a variety of tungsten a-zirconia (WO3/ZrO2) catalysts of different W/Zr ratios using different calcination temperatures is studied at 473 K using a continuous fixed-bed reactor at atmospheric pressure. The maximum activity for ethene hydration is obtained by calcination at 1073 K with a W/Zr ratio of 0.4, while skeletal isomerization of n-butane is found to exhibit a maximum rate at W/Zr = 0.1. The most active WO3/ZrO2 catalysts is demonstrated to be superior in activity to other typical solid acids such as H4SiW12O40/SiO2, zeolites (H-ZSM-5 and H-beta), various mixed oxides, and polymer resins. Lifetime tests reveal that constant activity of Wo(3)/ZrO2 obtained at 72 h is about 70% of initial activity and that the activity is largely recovered by calcination at 773 K in air. The specific activity (per surface area) of WO3/ZrO2 is correlated with the hydrophobicity as estimated from the adsorption of water rather than with that estimated from the density of acid sites measured by NH3-TPD. Therefore, the pronounced activity Of WO3/ZrO2 is mainly brought about by the high hydrophobicity of the surface along with the inherent acidity. (C) 2003 Elsevier B.V. All rights reserved.
  • T Echizen, T Suzuki, Y Kamiya, T Okuhara
    JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL 209 1-2 145 - 153 2004年02月 [査読有り][通常論文]
     
    The reaction mechanism of skeletal isomerization of n-butane over typical solid acids such as CS2.5H0.5PW12O40, sulfated ZrO2, and WO3/ZrO2 and their Pt-promoted catalysts have been studied by the use of 1,4-C-13(2)-n-butane. Isotopic distributions in product isobutane and reactant n-butane were quantitatively analyzed by field-ionization mass spectrometry (FI-MS). On these solid acids, below 423 K, isobutane consisted of C-13(0)-C-13(4) isotopes, whose distributions were close to the corresponding binomial distributions, with the reactant n-butane being mainly C-13(2)-n-butane. This indicates that the isomerization proceeded with an intermolecular rearrangement through a bimolecular mechanism. In the temperature range of 493-523 K over these solid acids, the isotopic distributions in isobutane deviated from the binomial distributions; the fractions of C-13(2)-isobutane were greater than those expected from the binomial distributions, showing that an intramolecular (monomolecular) rearrangement became significant. Further, the product isobutane was found to consist of exclusively C-13(2)-isobutane over these Pt-promoted catalysts in the presence of 112, demonstrating the operation of a monomolecular mechanism on the bifunctional catalysts. (C) 2003 Elsevier B.V. All rights reserved.
  • Kamiya, Y., Hiyoshi, N., Ryumon, N., Okuhara, T.
    Journal of Molecular Catalysis A: Chemical 220 1 103 - 112 2004年 [査読有り][通常論文]
  • Hiyoshi, N., Yamamoto, N., Ryumon, N., Kamiya, Y., Okuhara, T.
    Journal of Catalysis 221 1 225 - 233 2004年 [査読有り][通常論文]
  • KAMIYA Y, SAKATA S, YOSHINAGA Y, OHNISHI R, OKUHARA T
    Catalysis Letters 94 1/2 45 - 47 2004年 [査読有り][通常論文]
  • MAO J, KAMIYA Y, OKUHARA T
    Applied Catalsis A, General 255 2 337 - 344 2003年12月 [査読有り][通常論文]
     
    A Friedel-Crafts-type reaction of 1,3,5-trimethylbenzene with gamma-butyrolactone was conducted over various solid acid catalysts such as zeolites, polymer resins, and heteropolyacids. The alkylation to 4-(2,4,6-trimethylphenyl) butyric acid proceeded exclusively with these catalysts; no acylation to the ketone occurred. The heteropolyacids, such as H3PW12O40 and H4SiW12O40, were superior in activity to the other catalysts; they also accelerated the reaction of the product acid with gamma-butyrolactone to the corresponding carboxylic acid. When the heteropolyacids were supported on silica, alkylation proceeded efficiently with high mass balance, suppressing further reaction. The reusability of the supported heteropolyacids also was confirmed. (C) 2003 Elsevier B.V. All rights reserved.
  • LS Li, Y Kamiya, T Okuhara
    APPLIED CATALYSIS A-GENERAL 253 1 29 - 32 2003年10月 [査読有り][通常論文]
     
    Synthesis of dipentaerythritol (DPE) by dehydration of pentaerythritol (PE) has been studied using heteropoly compounds and various solid acids. Heteropoly compounds such as H3PW12O40, H4SiW12O40 and their supported catalysts were found to be effective. The addition of water in the reactant suppressed the consecutive reaction of dipentaerythritol with pentaerythritol over H3PW12O40. Under atmospheric pressure at 463 K, silica-supported H3PW12O40 gave 30% yield, while zeolites (H-beta, H-mordenite, and H-Y) and SiO2-Al2O3 were inactive. Turnover number reached 31 over 20 wt.% H3PW12O40/SiO2, indicating that this reaction took place catalytically on it. (C) 2003 Elsevier B.V. All rights reserved.
  • Y Kamiya, Y Kijima, T Ohkura, A Satsuma, T Hattori
    APPLIED CATALYSIS A-GENERAL 253 1 1 - 13 2003年10月 [査読有り][通常論文]
     
    Intercalation of Fe(acac)3 into lamellar vanadyl n-hexylphosphate, VO{(n-C6H13)(0.6)/H-0.4}PO4.(n-C6H13OH)(0.5) followed by calcination, has been investigated for preparation of Fe-doped (VO)(2)P2O7 catalyst; selective oxidation of n-butane to maleic anhydride was performed. Fe(acac)3 was successfully intercalated into the vanadyl n-hexylphosphate by heating in toluene. The obtained precursor was transformed to single phase (VO)(2)P2O7 by a calcination at 823 K in the presence of a mixture of 5% n-butane and 20% O-2, in N-2 (balance). The doped Fe ions uniformly spread in the bulk of the catalyst and were substituted for V4+ in the (VO)(2)P2O7 crystal. The catalytic activity for maleic anhydride formation per unit surface area on the Fe-doped catalyst was higher than that on the Fe-free catalyst prepared by calcination of the vanadyl n-hexylphosphate. Rates of reduction with n-butane and re-oxidation with air in the top few surface layers of the catalysts were estimated from weight decreases and increases detected on a TG/DTA apparatus. The Fe-doped catalysts gave high rates of both the reduction and re-oxidation. especially re-oxidation. XPS studies confirmed that the surface of the Fe-doped catalysts was in a higher oxidation state under the steady state of the reaction. In addition, the Fe-doped catalysts showed a smaller reaction order on partial pressure of O-2. Therefore, the doped Fe can enhance the redox ability, especially the re-oxidation, of the catalyst, resulting in the high catalytic performance. (C) 2003 Published by Elsevier B.V.
  • Y Kamiya, E Nishikawa, A Satsuma, T Okuhara
    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 76 4 837 - 846 2003年04月 [査読有り][通常論文]
     
    Vanadyl alkylphosphates consisting of V4+ and p(5+) were synthesized by the reaction of a solid mixture of V,05 and V4O9 (2:3 in mol) with P2O5 in primary aliphatic (from C-1 to C-8), secondary aliphatic (C-3 and C-4), and alicyclic (C-5) alcohols, and were characterized by means of elemental analysis, thermogravimetric analysis, X-ray diffraction, IR spectroscopy, and magnetic susceptibility. The chemical formulae of the products were determined to be VO(RO)(3)(HO)(1-x)PO3.(ROH)(3) (x = 0.5-0.7, y = 0.3-0.5 for primary aliphatic alcohols x = 0.1-0.2. y = 0.4-0.9 for secondary aliphatic and alicyclic alcohols: and R = organic group), X-ray diffraction revealed that the compounds had a lamellar structure, where the organic groups existed as double layers with a tilt of about 56 against the basal plane. Magnetism and IR spectroscopy demonstrated that the construction of the basal planes in the vanadyl alkylphosphates was similar to that of VOHPO4.0.5H(2)O, which consists of V4+ dimers linked with PO4, except for vanadyl sec-butylphosphate. consisting of isolated V4+ monomers. Calcination of vanadyl methylphosphate and vanadyl cyclopentylphosphate brought about crystallites of (VO)(2)P2O7. These (VO)(2)P2O7 exhibited high selectivities to maleic anhydride (65-68%) for the selective oxidation of butane under a high concentration of butane (5.0%).
  • Yuichi Kamiya, Satoshi Ueki, Norihito Hiyoshi, Naoki Yamamoto, Toshio Okuhara
    Catalsis Today 78 1-4 SPEC. 281 - 290 2003年 [査読有り][通常論文]
  • Y Kamiya, H Nishiyama, M Yashiro, A Satsuma, T Hattori
    JOURNAL OF THE JAPAN PETROLEUM INSTITUTE 46 1 62 - 68 2003年01月 [査読有り][通常論文]
     
    Acidic properties of three types of (VO)(2)P2O7 Catalysts were investigated by temperature programmed desorption (TPD) using 3,5- and 2,6-dimethylpyridine as probes, and the selective oxidation of butane to maleic anhydride (MA) was performed. VPO-org was prepared in organic solvent, VPO-redu was obtained by reduction of VOPO4.2H(2)O, and VPO-aq was prepared in aqueous medium. 3,5-Dimethylpyridine (3,5-DMP) is adsorbed on both Bronsted and Lewis acid sites, whereas 2,6-dimethylpyridine (2,6-DMP) is selectively adsorbed on Bronsted acid sites due to the steric hindrance of the two methyl groups, so the amounts and strengths of the Bronsted and Lewis acid sites could be determined separately. The (VO)(2)P2O7 catalysts had four types of acid sites: weak and strong Bronsted acid sites, and weak and strong Lewis acid sites. The acidic properties were greatly dependent on the preparation methods as follows: VPO-org had a larger amount of the strong Bronsted acid sites and these acid sites were relatively weak. VPO-redu had a larger amount of the strong Lewis acid sites and VPO-aq had fewer acid sites. The selectivity to MA at low conversion increased with the amount of strong Lewis acid sites, indicating that the strong Lewis acid sites are important for MA formation. The strong Bronsted acid sites may promote the consecutive oxidation of MA.
  • Y Kamiya, E Nishikawa, A Satsuma, M Yoshimune, T Okuhara
    MICROPOROUS AND MESOPOROUS MATERIALS 54 3 277 - 283 2002年07月 [査読有り][通常論文]
     
    Highly porous vanadium phosphorus oxides (V-P oxides) of high specific surface area were synthesized by thermal treatment of layered vanadyl n-butylphosphate in M. The surface area of V-P oxides was greatly increased by thermal treatment within a temperature range of 500-550 K, and reached 225 m(2) g(-1) after treatment at 568 K. The N-2 adsorption-desorption isotherm of V-P oxide is a Type IV isotherm, indicating that this material is mesoporous. Micropore and mesopore size distributions were determined from Saito-Foley analysis using an Ar adsorption isotherm and Dollimore-Heal analysis using an N-2 desorption isotherm, respectively. The pores show a bimodal distribution in the micropore and mesopore region, and the micropores show a broad distribution with small volume (0.004 cm(3) g(-1)). The mesopores, which have a size of 4.4 nm and a volume of 0.272 cm(3)g(-1), were probably formed from fractures of microcrystallites along layers of vanadyl n-butylphosphate. (C) 2002 Elsevier Science Inc. All rights reserved.
  • A Satsuma, Y Kijima, S Komai, Y Kamiya, E Nishikawa, T Hatttori
    CATALYSIS TODAY 71 1-2 161 - 167 2001年11月 [査読有り][通常論文]
     
    A novel approach for preparation of promoted vanadium-phosphorous oxide (VPO) in well-defined structure was examined. Lamellar vanadyl benzylphosphate (LVPO) was used as a host material and Fe-complex as a guest. It was found that Fe-complex was successfully inserted into LVPO by heating of LVPO and Fe(acac)(3) in toluene solution. The obtained material was characterized by means of XRD, TEM, EDX, XPS, and FT/IR. It was confirmed that Fe(acac)(3) was uniformly dispersed in the interlayer of LVPO without significant distraction of lamellar structure of parent LVPO. (C) 2001 Elsevier Science B.V. All rights reserved.
  • Y Kamiya, E Nishikawa, A Satsuma, N Mizuno, T Okuhara
    SEKIYU GAKKAISHI-JOURNAL OF THE JAPAN PETROLEUM INSTITUTE 44 4 265 - 266 2001年07月 [査読有り][通常論文]
     
    Layered vanadyl alkylphosphates, where the alkyl groups are not only straight-chain but also branched and cyclic ones, were prepared by reaction of a mixture of V2O5 and V4O0 with P2O5 in alcohol. The distances between layers of the vanadyl alkylphosphates increased linearly as the length of the alcohol increased. The (VO)(2)P2O7 catalyst obtained by calcination of vanadyl methylphosphate exhibited a high performance in the oxidation of n-butane to maleic anhydride.
  • Hiyoshi, N., Yamamoto, N., Kamiya, Y., Nishikawa, E., Okuhara, T.
    Catalysis Today 71 1-2 129 - 135 2001年 [査読有り][通常論文]
  • Y Kamiya, E Nishikawa, T Okuhara, T Hattori
    APPLIED CATALYSIS A-GENERAL 206 1 103 - 112 2001年01月 [査読有り][通常論文]
     
    Selective oxidation of n-butane to maleic anhydride was studied at high concentrations of n-butane up to 5.0 vol.% using three kinds of (VO)(2)P2O7 catalysts having differently shaped microcrystallites; rose-petals (catalyst A), plates (catalyst B), and blocks (catalyst C). The catalytic activity for maleic anhydride formation per unit surface area greatly depended on the kinds of catalysts at the high concentration of n-butane (5.0 vol.%); catalyst A was much more active, while there was no difference at the low concentrations. That catalyst A gave higher rates of the re-oxidation and reduction, which was established from the measurements of reduction of the catalyst, aged in the reaction mixture, with n-butane and subsequently re-oxidation with O-2. In addition, catalyst A showed a larger reaction order of n-butane concentration. Therefore, the higher catalytic performance of catalyst A at the high concentration of n-butane is attributed to the higher redox ability of the catalyst, and this is probably brought about from the structural disorder of the surface. (C) 2001 Elsevier Science B.V. All rights reserved.
  • A Satsuma, Y Kamiya, Y Westi, T Hattori
    APPLIED CATALYSIS A-GENERAL 194 253 - 263 2000年03月 [査読有り][通常論文]
     
    Temperature-progammed desorption of dimethylpyridine (DMP-TPD) was performed for the measurement of strength of Bronsted acid-and Lewis acid sites on metal oxide catalysts. Alumina, alumina-boria, silica-magnesia and silica-alumina were employed as examples of solid acid catalysts. Infrared (IR) spectra of adsorbed pyridine (Py) and ammonia showed that Lewis acid sites were abundant on alumina, Bronsted acid sites were abundant on alumina-boria, and both were present on silica-magnesia and silica-alumina surfaces. 2,6-dimethylpyridine-TPD (2,6-DMP-TPD) spectra of alumina depended strongly on purging temperatures. The amount of desorbed 2,6-DMP decreased with the increase in the purging temperature, and only a negligible amount of 2,6-DMP was detected in the TPD run from 523 K. On the other hand, 3,5-dimethylpyridine (3,5-DMP) adsorbed on Lewis acid sites on alumina. Selective adsorption of 2,6-DMP on Lewis acid sites was also confirmed from in-situ IR spectra. In the case of alumina-boria on which Bronsted acid sites are abundant, both 2,6-DMP-TPD and 3,5-DMP-TPD spectra gave similar desorption profiles. Profiles of acid strength determined from DMP-TPD agreed well with those determined from the IR spectra of adsorbed 3,5-DMP. These results demonstrated the selective adsorption of 2,6-DMP on Bronsted acid sites because of steric hindrance of methyl groups, and the possibility of measurement of respective strength of Bronsted acid and Lewis acid sites. Through a comparison of 2,6-DMP-TPD and 3,5-DMP-TPD spectra of silica-magnesia and:silica-alumina, the scope of DMP-TPD for the measurement of strength of Bronsted and Lewis acid sites on metal oxide catalysts was discussed. (C) 2000 Elsevier Science B.V. All rights reserved.
  • Atsushi Satsuma, Naruaki Sugiyama, Yuichi Kamiya, Tadashi Hattori
    Studied in Surface Science and Catalysis 130 1799 - 1804 2000年 [査読有り][通常論文]
  • A Satsuma, Y Westi, Y Kamiya, T Hattori, Y Murakami
    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 70 6 1311 - 1317 1997年06月 [査読有り][通常論文]
     
    The temperature-programmed desorption of pyridine (Py-TPD) was performed for measuring the acid strength and acid amount of binary oxide catalysts. First, the optimum measurement conditions were determined by comparing the TPD spectra with the infrared spectra of adsorbed pyridine measured under the same conditions in order to minimize the shift in the desorption temperature and contribution of physically absorbed and/or weakly held pyridine. The following conditions were found to be optimum: purging at 423 K for 2 h, W/F (W, sample weight; F, flow rate of the carrier) of 100 mg/150 cm(3) min(-1), and a heating rate of 5 K min(-1). This method was applied then to a series of binary mixed oxide catalysts. The amount of desorbed pyridine was 15-24% of the full coverage of pyridine on the catalyst surface with few exceptions. The highest acid strength, determined from the Py-TPD spectra, was well-correlated to that determined from a color change of Hammett indicators. The potential of the Py-TPD for determining the acid strength and the acid amount on binary oxide catalysts is discussed.
  • A Satsuma, N Sugiyama, Y Kamiya, T Hattori
    CHEMISTRY LETTERS 10 1051 - 1052 1997年 [査読有り][通常論文]
     
    Silica species prepared by in-situ method using silicon alkoxide as precursor were found to be active for radical type oxidation of butane at low temperatures, i.e., below 650 K.

書籍

  • 固定化触媒のルネッサンス
    株式会社シーエムシー出版 2007年
  • 環境修復の科学と技術
    北海道大学出版会 2007年
  • エコマテリアルハンドブック
    丸善株式会社 2006年
  • Encyclopedia of Inorganic Chemistry-2nd Edition
    John Wiley & Sons, Ltd, 2005年
  • 表面・界面工学大系(下巻)
    株式会社テクノシステム 2005年

その他活動・業績

  • MoO3-ZrO2 触媒の調製、WO3-ZrO2 触媒の調製、H4SiW12O40/SiO2 触媒の調製、(VO)2P2O7 触媒の調製、VOPO4 ナノシートの合成とそれを原料とする(VO)2P2O7触媒の調製
    神谷 裕一共著 触媒調製ハンドブック 130-133,166 -167,176-179 2011年04月 [査読有り][通常論文]
  • How to prepare heterogenesous and homogeneous catalysts
    2011年 [査読無し][通常論文]
  • Yuichi Kamiya, Hiroyuki Imai, Toshio Okuhara J. Jpn. Petrol. Inst. 52 (3) 81 -89 2009年 [査読有り][通常論文]
  • 水処理
    神谷 裕一共著 触媒便覧 2008年09月 [査読有り][通常論文]
  • 環境超強酸
    神谷 裕一共著 触媒便覧 2008年09月 [査読有り][通常論文]
  • 層状化合物の層剥離―還元法によるピロリン酸ジバナジル触媒とそのブタン選択酸化反応特性
    神谷 裕一 ペトロテック 31 (11) 881 -885 2008年 [査読有り][通常論文]
  • 水中固体酸を用いるグリーン化学プロセス
    神谷 裕一, 奥原 敏夫 固体化触媒のルネッサンス 125 -125 2007年07月 [査読有り][通常論文]
  • 層剥離-還元を利用した結晶性バナジウム-リン複合酸化物触媒の合成とn-ブタン選択酸化反応特性
    神谷 裕一, 奥原 敏夫 触媒 49 (7) 548 -548 2007年 [査読有り][通常論文]
  • ヘテロポリ酸を用いた水中固体酸触媒
    神谷 裕一, 奥原 敏夫 エコマテリアルハンドブック 2006年12月 [査読有り][通常論文]
  • 環境修復のための技術と科学
    第4章-2 2006年 [査読有り][通常論文]
  • ヘテロポリ酸塩および薄層担持ヘテロポリ酸触媒によるクリーン化学合成
    神谷 裕一, 奥原 敏夫 環境管理 42 (7) 26 -26 2006年 [査読有り][通常論文]
  • 水の中で機能する固体酸触媒
    神谷 裕一, 奥原 敏夫 触媒 48 (1) 15 -15 2006年 [査読有り][通常論文]
  • Oxide Catalysts in Solid State Chemistry
    Encyclopedia of Inorganic Chemistry-2nd Edition, Jhon Wiley & Sons, Ltd, 2005年11月 [査読有り][通常論文]
  • ヘテロポリ酸の酸触媒作用に及ぼす担体の影響
    神谷 裕一, 奥原 敏夫 触媒 47 (1) 32 -32 2005年 [査読有り][通常論文]
  • 化学プロセスのゼロエミッション化
    神谷 裕一, 奥原 敏夫 表面・界面工学大系 下 255 -260 2005年 [査読有り][通常論文]
  • 固体触媒上での長鎖アルカンの分子状酸素による選択酸化
    神谷 裕一 触媒 46 (3) 255 -255 2004年 [査読有り][通常論文]

特許

  • ヘテロポリ酸のアルカリ金属塩及びそれらからなるオレフィンオリゴマー化用触媒
    特開2010-260768
  • アルキル芳香族化合物の製造方法
    特開2007-77133
  • アルキル芳香族化合物の製造方法
    特開2007-77132
  • 撥水性を有する貴金属含有触媒
    特許第4759731号
  • ヘテロポリ酸塩と無機酸化物とから成る組成物及びその製造法
    特許第4524427号
  • 特願WO2008032459-A1:Organic group-bounded acidic catalyst for fragrance and pharmaceuticals, has organic group(s) coupled together on surface of solid catalyst.  
    Kei Inumaru, Toru Ishihara, Toshio Okuhara, Yuichi Kamiya
  • 特願2006-248413:有機基結合酸触媒  
    犬丸 啓, 石原 亨, 奥原 敏夫, 神谷 裕一
  • 特願2005-237219:アルキルベンゼンの製造方法  
    日比 卓男, 奥原 敏夫, 神谷 裕一
  • 特願2005-237218:アルキルベンゼンの製造方法  
    日比 卓男, 奥原 敏夫, 神谷 裕一

受賞

  • 2008年05月 石油学会 平成19年度石油学会奨励賞
     "層状化合物を前駆体とする結晶性バナジウムーリン複合酸化物触媒の合成とその選択酸化触媒作用に関する研究"
  • 2004年 13th International Congress on Catalysis Young Scientist Prize of the International Association of Catalysis Societies (13 the International Congress on Catalysis)
     "Nano-sized(VO)2P2O7 crystallites of unprecedented selectivity for n-butane oxidation synthesized by exfoliation of VOPO4 2H2O"
  • 2004年 Young Scientist Prize of the International Association of Catalysis Societies (13th International Congress on Catalysis)

共同研究・競争的資金等の研究課題

  • 硝酸イオン汚染地下水の浄化に真に貢献する亜鉛添加ニッケル触媒の開発
    科学研究費補助金 基盤研究(B)
    研究期間 : 2018年04月 -2021年03月 
    代表者 : 神谷 裕一
  • 小規模施設に適したアンモニア態窒素含有廃水高度処理のための高性能触媒の開発
    住友財団: 環境研究助成
    研究期間 : 2016年11月 -2017年11月 
    代表者 : 神谷 裕一
  • 廃水中のアンモニアを温和な温度で酸化分解する高性能固体触媒の開発
    科学研究費補助金 基盤研究(C)
    研究期間 : 2014年04月 -2016年03月 
    代表者 : 神谷 裕一
  • 機能性原子団を導入した分子性酸化物アニオンで構成されたイオン結晶の触媒機能
    科学研究費補助金 若手研究B
    研究期間 : 2012年04月 -2014年03月 
    代表者 : 神谷 裕一
  • 水資源の永続的確保のための水中硝酸イオン還元無害化に関する研究
    住友財団:環境研究助成
    研究期間 : 2009年11月 -2010年10月 
    代表者 : 神谷 裕一
  • 硝酸イオンと汚染水の触媒法浄化における水中共雑物び影響とその対策に関する研究
    科学研究費補助金 基盤研究C
    研究期間 : 2008年04月 -2010年03月 
    代表者 : 神谷 裕一
  • 環状アルカンの高選択的水素化開環触媒の開発とクリーガソリン合成への適用
    石油学会:研究助成
    研究期間 : 2007年04月 -2008年03月 
    代表者 : 神谷 裕一
  • 農業汚染地下水復元のためのナノクラスタ触媒システムの開拓
    科学研究費補助金 基盤研究C
    研究期間 : 2005年04月 -2007年03月 
    代表者 : 奥原 敏夫, 神谷 裕一
  • クリーン化学合成のための新規ナノコンポジット水中固体酸触媒の開発
    科学研究費補助金 若手研究B
    研究期間 : 2005年04月 -2007年03月 
    代表者 : 神谷 裕一
  • Clean synthesis using solid catalysts

教育活動情報

主要な担当授業

  • ナノ環境材料化学特論Ⅰ
    開講年度 : 2018年
    課程区分 : 修士課程
    開講学部 : 環境科学院
    キーワード : 触媒化学、環境修復、グリーンケミストリー、大気化学、オゾン層、オゾンホール、光化学オキシダント、反応速度論 Catalytic chemistry, Environmental remediation, Green sustainable chemistry, Atmospheric chemistry, Ozone layer, Ozone hole, Photochemical oxidant, Chemical kinetics
  • 化学Ⅰ
    開講年度 : 2018年
    課程区分 : 学士課程
    開講学部 : 全学教育
    キーワード : 原子の構造、原子軌道、化学結合、混成軌道、物質の三態、電解質溶液


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