Researcher Database

Andrey Lyalin
Creative Research Institution Institute for Chemical Reaction Design and Discovery
Specially Appointed Associate Professor

Researcher Profile and Settings

Affiliation

  • Creative Research Institution Institute for Chemical Reaction Design and Discovery

Job Title

  • Specially Appointed Associate Professor

Degree

  • PhD(St Petersburg State University, Russia)

J-Global ID

Research Interests

  • Computational chemistry   Physical chemistry   Materials science   Electrocatalysis   Heterogeneous catalyst   Nanocatalysis   Nanoscience   Catalysis   Theoretical chemistry   Clusters   Theoretical physics   

Research Areas

  • Nanotechnology/Materials / Nanomaterials
  • Natural sciences / Bio-, chemical, and soft-matter physics
  • Nanotechnology/Materials / Basic physical chemistry

Academic & Professional Experience

  • 2019/04 - Today Hokkaido University Institute for Chemical Reaction Design and Discovery Associate Professor
  • 2015/04 - 2019/03 National Institure for Materials Science GREEN Special Researcher
  • 2013/01 - 2015/03 Kyoto University ESICB Assistant professor
  • 2001/01 - 2014/12 St Petersburg State University, Russia V. A. Fock Institute of Physics Senior Scientist
  • 2010 - 2012 北海道大学 理学(系)研究科(研究院) その他
  • 2002/02 - 2004/12 J.-W. Goethe University, Frankfurt am Main, Germany Institute for Theoretical Physics Alexander von Humboldt Fellowship
  • 2000/01 - 2000/12 Imperial College London, UK Department of Physics The Royal Society/NATO Fellowship

Education

  • 1986/09 - 1995/04  St Petersburg State University, Russia  Faculty of Physics

Research Activities

Published Papers

  • Ken Sakaushi, Andrey Lyalin, Tetsuya Taketsugu
    Current Opinion in Electrochemistry 19 96 - 105 2451-9103 2020/02 [Refereed][Not invited]
  • Nikolay A. Vinogradov, Andrey Lyalin, Tetsuya Taketsugu, Alexander S. Vinogradov, Alexei Preobrajenski
    ACS Nano 13 (12) 14511 - 14518 1936-0851 2019/12/24 [Refereed][Not invited]
  • Debnath Sreekanta, Song Xiaowei, Fagiani Matias R, Weichman Marissa L, Gao Min, Maeda Satoshi, Taketsugu Tetsuya, Schoellkopf Wieland, Lyalin Andrey, Neumark Daniel M, Asmis Knut R
    JOURNAL OF PHYSICAL CHEMISTRY C American Chemical Society ({ACS}) 123 (13) 8439 - 8446 1932-7447 2019/04/04 [Refereed][Not invited]
  • M. Eckardt, K. Sakaushi, A. Lyalin, M. Wassner, N. Hüsing, T. Taketsugu, R. J. Beh
    Electrochimica Acta 299 736 - 748 0013-4686 2019/03/10 [Not refereed][Not invited]
     
    © 2019 Elsevier Ltd Aiming at a better understanding of the molecular scale mechanism of the oxygen reduction reaction (ORR) on metal-free catalysts, we have systematically investigated this reaction in a combined experimental and theoretical approach on a set of catalysts consisting of nitrided carbon spheres. These catalysts, which were prepared similarly, but applying different carbonization/nitriding temperatures, were studied in acidic and alkaline electrolyte. The physical properties characterization of both, the bulk materials and the surface, was performed by transmission electron microscopy (TEM), N 2 sorption, X-ray photoelectron spectroscopy (XPS), CHN analysis and energy dispersive X-ray spectroscopy (EDX) and Temperature Programmed Desorption (TPD) of CO 2 . Electrochemical and –catalytic properties were characterized by rotating ring disk electrode (RRDE) measurements. Mechanistic aspects were explored by kinetic analysis of the ORR and by evaluation of the kinetic isotope effect (H-D exchange), using deuterated electrolytes (KOD and D 2 SO 4 ). In combination with density functional theory based calculations, these kinetic data provide detailed insights into the reaction mechanism and its dependence on pH effects. In acidic electrolyte, the first proton coupled electron transfer (PCET) is identified as rate determining step (RDS), while in alkaline electrolyte the first electron transfer (ET) to O 2∗−ad is rate determining, followed by fast protonation. The potential of these highly active catalysts and the influence of structural effects are discussed.
  • Lyalin Andrey, Kuznetsov Vladimir G, Nakayama Akira, Abarenkov Igor V, Tupitsyn Ilya I, Gabis Igor E, Uosaki Kohei, Taketsugu Tetsuya
    JOURNAL OF THE ELECTROCHEMICAL SOCIETY 166 (3) A5362 - A5368 0013-4651 2019/01/19 [Refereed][Not invited]
  • Iwasa Takeshi, Sato Takaaki, Takagi Makito, Gao Min, Lyalin Andrey, Kobayashi Masato, Shimizu Ken-ichi, Maeda Satoshi, Taketsugu Tetsuya
    JOURNAL OF PHYSICAL CHEMISTRY A American Chemical Society ({ACS}) 123 (1) 210 - 217 1089-5639 2019/01/10 [Refereed][Not invited]
  • Sakaushi Ken, Lyalin Andrey, Taketsugu Tetsuya, Uosaki Kohei
    Phys. Rev. Lett. American Physical Society 121 (23) 236001  0031-9007 2018/12/07 [Refereed][Not invited]
  • K. A. Simonov, A. V. Generalov, A. S. Vinogradov, G. I. Svirskiy, A. A. Cafolla, C. McGuinness, T. Taketsugu, A. Lyalin, N. Mårtensson, A. B. Preobrajenski
    Scientific Reports 8 (1) 3506  2045-2322 2018/12/01 [Refereed][Not invited]
     
    We investigate the bottom-up growth of N = 7 armchair graphene nanoribbons (7-AGNRs) from the 10,10′-dibromo-9,9′-bianthracene (DBBA) molecules on Ag(111) with the focus on the role of the organometallic (OM) intermediates. It is demonstrated that DBBA molecules on Ag(111) are partially debrominated at room temperature and lose all bromine atoms at elevated temperatures. Similar to DBBA on Cu(111), debrominated molecules form OM chains on Ag(111). Nevertheless, in contrast with the Cu(111) substrate, formation of polyanthracene chains from OM intermediates via an Ullmann-type reaction is feasible on Ag(111). Cleavage of C-Ag bonds occurs before the thermal threshold for the surface-catalyzed activation of C-H bonds on Ag(111) is reached, while on Cu(111) activation of C-H bonds occurs in parallel with the cleavage of the stronger C-Cu bonds. Consequently, while OM intermediates obstruct the Ullmann reaction between DBBA molecules on the Cu(111) substrate, they are required for the formation of polyanthracene chains on Ag(111). If the Ullmann-type reaction on Ag(111) is inhibited, heating of the OM chains produces nanographenes instead. Heating of the polyanthracene chains produces 7-AGNRs, while heating of nanographenes causes the formation of the disordered structures with the possible admixture of short GNRs.
  • Sakaushi Ken, Eckardt Markus, Lyalin Andrey, Taketsugu Tetsuya, Behm R. Juergen, Uosaki Kohei
    ACS CATALYSIS American Chemical Society ({ACS}) 8 (9) 8162 - 8176 2155-5435 2018/09 [Refereed][Not invited]
  • Theoretical suggestion and experimental proof for functionalization of h-BN by gold as electrocatalysts for ORR and HER
    Taketsugu Tetsuya, Lyalin Andrey, Gao Min, Uosaki Kohei
    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY 256 0065-7727 2018/08/19 [Refereed][Not invited]
  • Andrey Lyalin, Vladimir G. Kuznetsov, Akira Nakayama, Igor V. Abarenkov, Ilya I. Tupitsyn, Igor E. Gabis, Kohei Uosaki, Tetsuya Taketsugu
    Journal of Physical Chemistry C 122 (20) 11096 - 11108 1932-7455 2018/05/24 [Refereed][Not invited]
     
    Because of its exceptional lithium storage capacity, silicon is considered as a promising candidate for anode material in lithium-ion batteries (LIBs). In the present work, we demonstrate that methods of soft X-ray emission spectroscopy can be used as a powerful tool for the comprehensive analysis of the electronic and structural properties of lithium silicides LixSi forming in LIB's anode upon Si lithiation. On the basis of density functional theory and molecular dynamics simulations, it is shown that the coordination number of Si atoms in LixSi decreases with an increase in Li concentration both for the crystalline and amorphous phases. In amorphous a-LixSi alloys, Si tends to cluster, forming Si-Si covalent bonds even at the high lithium concentration. It is demonstrated that the Si-L2,3 emission bands of the crystalline and amorphous LixSi alloys show different spectral dependencies, reflecting the process of disintegration of Si-Si network into Si clusters and chains of the different sizes upon Si lithiation. The Si-L2,3 emission bands of LixSi alloys become narrower and shift toward higher energies with an increase in Li concentration. The shape of the emission band depends on the relative contribution of the X-ray radiation from the Si atoms having different coordination numbers. This feature of the Si-L2,3 spectra of LixSi alloys can be used for the detailed analysis of the Si lithiation process and LIB's anode structure identification.
  • Andrey Lyalin, Kohei Uosaki, Tetsuya Taketsugu
    Electrocatalysis 9 (2) 182 - 188 1868-5994 2018/03/01 [Refereed][Not invited]
     
    The catalytic activity for the oxygen reduction reaction (ORR) of a hexagonal boron nitride (h-BN) monolayer deposited on a Au(111) surface and decorated by a small planar Au8 cluster has been studied theoretically using density-functional theory. It is shown that gold nanoparticles (Au-NP) deposited on the h-BN/Au(111) surface can provide catalytically active sites for effective ORR at the perimeter interface with the support. Stabilization of oxygen at the perimeter interface between Au-NP and h-BN/Au(111) support promotes OOH* dissociation opening effective 4-electron pathway of ORR with formation of H2O. It is suggested that increase in the perimeter interface area between the supported Au-NP and the surface would result in increase of the ORR activity. Such increase in the perimeter interface area can be achieved by decreasing the size of Au-NP. Our calculations demonstrate the principal ability to functionalize inert materials such as stand-alone h-BN monolayer or Au surface for the ORR and open new way to design effective Pt-free catalysts for fuel cell technology. [Figure not available: see fulltext.].
  • Xiaowei Song, Matias R. Fagiani, Sreekanta Debnath, Min Gao, Satoshi Maeda, Tetsuya Taketsugu, Sandy Gewinner, Wieland Schoellkopf, Knut R. Asmis, Andrey Lyalin
    PHYSICAL CHEMISTRY CHEMICAL PHYSICS 19 (34) 23154 - 23161 1463-9076 2017/09 [Refereed][Not invited]
     
    The mechanism of dissociative D-2 adsorption on Ti2O4-, which serves as a model for an oxygen vacancy on a titania surface, is studied using infrared photodissociation spectroscopy in combination with density functional theory calculations and a recently developed single-component artificial force induced reaction method. Ti2O4- readily reacts with D-2 under multiple collision conditions in a gas-filled ion trap held at 16 K forming a global minimum-energy structure (DO-Ti-(O)(2)-Ti(D)-O)(-). The highly exergonic reaction proceeds quasi barrier-free via several intermediate species, involving heterolytic D-2-bond cleavage followed by D-atom migration. We show that, compared to neutral Ti2O4, the excess negative charge in Ti2O4- is responsible for the substantial lowering of the D-2 dissociation barrier, but does not affect the molecular D-2 adsorption energy in the initial physisorption step.
  • Ken Sakaushi, Andrey Lyalin, Satoshi Tominaka, Tetsuya Taketsugu, Kohei Uosaki
    ACS NANO 11 (2) 1770 - 1779 1936-0851 2017/02 [Refereed][Not invited]
     
    The material choice for efficient electrocatalysts is limited because it is necessary to be highly active as well as highly stable. One direction to solve this issue is to understand elementary steps of electrode processes and build an unconventional strategy for a conversion of inert and, therefore, stable materials into efficient catalysts. Herein, we propose a simple concept for obtaining catalysts from inert and hence stable materials by forming their heterojunctions, namely, covering inert Au with corrugated carbon nitrogen-based two-dimensional porous frameworks. It shows more than 10 times better activity for the hydrogen evolution reaction than for the pure Au surface, and it also demonstrates the high catalytic activity for the oxygen reduction reaction (ORR) via an effective four-electron reduction mechanism, which is different from the usual two electron reduction typical for ORR on Au surfaces. This activity induced by formation of a heterojunction was analyzed by a conjugation of computational and experimental methods and found to originate from alternative efficient reaction pathways that emerged by the corrugated porous framework and the Au surface. This work provides not only the method for creating active surface but also the knowledge on elementary steps of such complicated multielectron transfer reactions, thereby leading to intriguing strategies for developing energy conversion reactions based on materials which had never been considered as catalysts before.
  • Min Gao, Daisuke Horita, Yuriko Ono, Andrey Lyalin, Satoshi Maeda, Tetsuya Taketsugu
    JOURNAL OF PHYSICAL CHEMISTRY C 121 (5) 2661 - 2668 1932-7447 2017/02 [Refereed][Not invited]
     
    A systematic investigation is performed on structural transformations in small neutral gold clusters (Au-3-Au-12) induced by O-2 adsorption, with the use of the fully automated reaction path search techniques, i.e., anharrnonic downward distortion following (APDF) and artificial force induced reaction (AFIR) methods, implemented in the global reaction route mapping (GRRM) program. For each size of Au cluster, the most stable structure, low-energy isomers, and a network of isomerization pathways are determined. The located Au-n-O-2 adsorption forms can be classified into two groups: eta(1)-AunO2, where only one oxygen atom is adsorbed on Au-n, and eta(2)=AunO2, where both oxygen atoms are adsorbed on Au-n in a hridged manner. These two adsorption forms can be transformed to eath other with a low barrier. The isornerization pathways of gold clusters upon O-2 adsorption are compared with those obtained for the pure gold cluSters Without O-2. It is demonstrated that O-2 adsorption promotes structural transformations in gold clusters considerably by lowering the isomerization battlers. The presence of the unpaired electron is a necessary condition for O-2 adsorption in the eta(1)-Au O-2 form, as well as the subsequent cluster isomerization and the O-O bond activation. These conclusions ate consistent with the recent experimental resits by Fielicke et al.
  • Andrey Lyalin, Ken-ichi Shimizu, Tetsuya Taketsugut
    JOURNAL OF PHYSICAL CHEMISTRY C 121 (6) 3488 - 3495 1932-7447 2017/02 [Refereed][Not invited]
     
    We present results of theoretical investigation on catalytic hydrogen elimination from isopropanol (C3H8O) by free and (theta-Al2O3(010)-supported Ni-13 cluster. The specific role played by the perimeter interface between the nickel cluster and alumina support is discussed. It is demonstrated that dehydrogenation of C3H8O on the free Ni-13 cluster is a two-step process with the first hydrogen elimination from the alcohol hydroxyl group, followed by C-H bond cleavage. Our calculations show that H elimination from OH group of C3H8O to Ni-13 cluster is the rate-determining step with the barrier of 0.95 eV, while the C-H bond cleavage requires overcoming the barrier of 0.41 eV. In the case of Ni-13 cluster supported on (theta-Al2O3(010) the isopropanol molecule adsorbs on top of the surface Al atom in the close vicinity of the nickel cluster, which results in considerable decrease in barrier for H elimination due to formation of the complementary adsorption sites at the metal/support interface. It is demonstrated that intermediate formation of the Ni-C bond considerably promotes C-H bond cleavage. The described mechanism provides fundamental understanding of the process of the oxidant-free catalytic hydrogen elimination from alcohols on supported nickel clusters and can serve as a tool for rational design of novel type of nanocatalysts based on abundant noble-metal-free materials.
  • Majharul Haque Khan, Sina S. Jamali, Andrey Lyalin, Paul J. Molino, Lei Jiang, Hua Kun Liu, Tetsuya Taketsugu, Zhenguo Huang
    ADVANCED MATERIALS 29 (4) 0935-9648 2017/01 [Refereed][Not invited]
     
    Outstanding protection of Cubyhigh-quality boron nitridenano film (B N N F) 1-2 atomic layers thick in salt water is observed, while defective BNNF accelerates the reaction of Cu toward water. The chemical stability, insulating nature, and impermeability of ions through the BN hexagons render BNNF a great choice for atomic-scale protection.
  • Andrey Lyalin, Min Gao, Tetsuya Taketsugu
    CHEMICAL RECORD 16 (5) 2324 - 2337 1527-8999 2016/10 [Refereed][Not invited]
     
    In this Personal Account, we review the work of our group in the area of environmental and energy-related nanocatalysis over the past seven years. We focus on understanding the fundamental mechanisms that control the properties of atomic clusters and nanoparticles - a form of matter that is intermediate between atoms and their bulk counterpart. The emphasis is on the theoretical design of effective catalysts based on cheap and abundant elements. The main idea that stands behind our work is that even catalytically inactive or completely inert materials can be functionalized at the nanoscale via the size, structure, morphology, and support effects. Such an approach opens up new ways to design catalytically active systems based on materials never before considered as catalysts. In particular, we demonstrate that hexagonal boron nitride (h-BN), which has been traditionally considered an inert material, can be functionalized and become active for a number of catalytic reactions involving oxygen activation, oxidation by molecular oxygen, and the oxygen reduction reaction.
  • Kohei Uosaki, Ganesan Elumalai, Hung Cuong Dinh, Andrey Lyalin, Tetsuya Taketsugu, Hidenori Noguchi
    SCIENTIFIC REPORTS 6 32217  2045-2322 2016/08 [Refereed][Not invited]
     
    It is demonstrated that electrochemical hydrogen evolution reaction ( HER) proceeds very efficiently at Au electrode, an inert substrate for HER, modified with BNNS, an insulator. This combination has been reported to be an efficient electrocatalyst for oxygen reduction reaction. Higher efficiency is achieved by using the size controlled BNNS (<1 mu m) for the modification and the highest efficiency is achieved at Au electrode modified with the smallest BNNS ( 0.1-0.22 mu m) used in this study where overpotentials are only 30 mV and 40 mV larger than those at Pt electrode, which is known to be the best electrode for HER, at 5 mAcm(-2) and at 15 mAcm(-2), respectively. Theoretical evaluation suggests that some of edge atoms provide energetically favored sites for adsorbed hydrogen, i.e., the intermediate state of HER. This study opens a new route to develop HER electrocatalysts.
  • Min Gao, Masashi Adachi, Andrey Lyalin, Tetsuya Taketsugu
    JOURNAL OF PHYSICAL CHEMISTRY C 120 (29) 15993 - 16001 1932-7447 2016/07 [Refereed][Not invited]
     
    Adsorption and catalytic activation of the molecular oxygen on the hexagonal boron nitride (h-BN) monolayer doped with carbon atom have been studied theoretically using density functional theory. It is demonstrated that C doping in B position of h-BN (C-B@h-BN) produces n-type semiconductor BN material with noticeable catalytic activity for O-2 activation in the large area extended far away from the C impurity. The adsorption energy of O2 on CB@h-BN decreasing slowly with the increase in distance from the CB defect, while O2 remains highly activated. No such effect is observed for monolayer h-BN doped with different atoms of group III, IV and V and transition-metal elements, such as B, N, Al, Si, Ge, Ni, Pt, Pd, and Au, where O-2 adsorbs only in the close vicinity of the dopant. It is shown that even small concentration of C dopants can functionalize the large surface area of monolayer BN making it promising catalytic material for oxygen activation and oxygen reduction reaction.
  • Ganesan Elumalai, Hidenori Noguchi, Andrey Lyalin, Tetsuya Taketsugu, Kohei Uosaki
    ELECTROCHEMISTRY COMMUNICATIONS 66 53 - 57 1388-2481 2016/05 [Refereed][Not invited]
     
    Overpotential for oxygen reduction reaction (ORR) at Au electrode is reported to be reduced by 0.27 V by the modification with boron nitride nanosheet (BNNS) but oxygen is reduced only to H2O2 by 2-electron process at Au electrode. Here we demonstrate that the decoration of BNNS with gold nanoparticles (AuNP) not only reduces the overpotential for ORR further by ca. 50 mV, but also opens a 4-electron reduction route to water. Both rotating disk electrode experiments with Koutecky-Levich analysis and rotating ring disk electrode measurements show that more than 50% of oxygen is reduced to water via 4-electron process at Au-BNNS/Au electrode while less than 20 and 10% of oxygen are reduced to water at the BNNS/Au and bare Au electrodes, respectively. Theoretical analysis of free energy profiles for ORR at the BN monolayer with and without Au-8 cluster placed on Au(111) shows significant stabilization of adsorbed oxygen atom by the Au-8 cluster, opening a 4-electron reduction pathway. (C) 2016 Elsevier B.V. All rights reserved.
  • Konstantin A. Simonov, Nikolay A. Vinogradov, Alexander S. Vinogradov, Alexander V. Generalov, Elena M. Zagrebina, Gleb I. Svirskiy, Attilio A. Cafolla, Thomas Carpy, John P. Cunniffe, Tetsuya Taketsugu, Andrey Lyalin, Nils Martensson, Alexei B. Preobrajenski
    ACS NANO 9 (9) 8997 - 9011 1936-0851 2015/09 [Refereed][Not invited]
     
    Bottom-up strategies can be effectively implemented for the fabrication of atomically precise graphene nanoribbons. Recently, using 10,10'-dibromo-9,9'-bianthracene (DBBA) as a molecular precursor to grow armchair nanoribbons on Au(111) and Cu(111), we have shown that substrate activity considerably affects the dynamics of ribbon formation, nonetheless without significant modifications in the growth mechanism. In this paper we compare the on-surface reaction pathways for DBBA molecules on Cu(111) and Cu(110). Evolution of both systems has been studied via a combination of core-level X-ray spectroscopies, scanning tunneling microscopy, and theoretical calculations. Experimental and theoretical results reveal a significant increase in reactivity for the open and anisotropic Cu(110) surface in comparison with the close-packed Cu(111). This increased reactivity results in a predominance of the molecular substrate interaction over the intermolecular one, which has a critical impact on the transformations of DBBA on Cu(110). Unlike DBBA on Cu(111), the Ullmann coupling cannot be realized for DBBA/Cu(110) and the growth of nanoribbons via this mechanism is blocked. Instead, annealing of DBBA on Cu(110) at 250 degrees C results in the formation of a new structure: quasi-zero-dimensional flat nanographenes. Each nanographene unit has dehydrogenated zigzag edges bonded to the underlying Cu rows and oriented with the hydrogen-terminated armchair edge parallel to the [1-10] direction. Strong bonding of nanographene to the substrate manifests itself in a high adsorption energy of -12.7 eV and significant charge transfer of 3.46e from the copper surface. Nanographene units coordinated with bromine adatoms are able to arrange in highly regular arrays potentially suitable for nanotemplating.
  • Min Gao, Andrey Lyalin, Makito Takagi, Satoshi Maeda, Tetsuya Taketsugu
    JOURNAL OF PHYSICAL CHEMISTRY C 119 (20) 11120 - 11130 1932-7447 2015/05 [Refereed][Not invited]
     
    This work present results of a systematic investigation of adsorption and dissociation of H-2 on the neutral, positively, and negatively charged gold clusters Au-n(q) (n = 2-11; q = 0; +/- 1) using the global reaction route mapping (GRRM) technique combined with the anharmonic downward distortion following (ADDF) and the artificial force-induced reaction (AFIR) methods. An exhaustive search for H-2 dissociation pathways is performed not only on the most stable cluster structures but also on the large number of low-energy isomers, allowing structural transformations between them. The present strategy can automatically identify the structure-dependent lowest transition states (TS) for H-2 dissociation with a systematic procedure in the regime of the structural fluxionality of gold clusters at finite temperature. Temperature effects, cluster isomerization, and influence of the charge state of gold clusters on H-2 adsorption and dissociation are studied. It is demonstrated that the most stable structures of the gold clusters are not always highly reactive, and an ensemble of isomeric structures must be taken into account for adequate description of the reaction rates at finite temperatures. The proposed approach can serve as a promising tool for a systematic analysis and prediction of reactivity of small metal clusters.
  • Andrey Lyalin, Akira Nakayama, Kohei Uosaki, Tetsuya Taketsugu
    TOPICS IN CATALYSIS 57 (10-13) 1032 - 1041 1022-5528 2014/06 [Refereed][Not invited]
     
    Adsorption and catalytic activation of the molecular oxygen on the hexagonal boron nitride (h-BN) monolayer supported on Ni(111) and Cu(111) surfaces have been studied theoretically using density functional theory. It is demonstrated that an inert h-BN monolayer can be functionalized and become catalytically active on the transition metal support as a result of mixing of the metal d and h-BN pi bands.
  • Kohei Uosaki, Ganesan Elumalai, Hidenori Noguchi, Takuya Masuda, Andrey Lyalin, Akira Nakayama, Tetsuya Taketsugu
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 136 (18) 6542 - 6545 0002-7863 2014/05 [Refereed][Not invited]
     
    Boron nitride (BN), which is an insulator with a wide band gap, supported on Au is theoretically suggested and experimentally proved to act as an electrocatalyst for oxygen reduction reaction (ORR). Density-functional theory calculations show that the band gap of a free h-BN monolayer is 4.6 eV but a slight protrusion of the unoccupied BN states toward the Fermi level is observed if BN is supported on Au(III) due to the BN-Au interaction. A theoretically predicted metastable configuration of O-2 on h-BN/Au(III), which can serve as precursors for ORR, and free energy diagrams for ORR on h-BN/Au(III) via two- and four-electron pathways show that ORR to H2O2 is possible at this electrode. It is experimentally proved that overpotential for ORR at the gold electrode is significantly reduced by depositing BN nanosheets. No such effect is observed at the glassy carbon electrode, demonstrating the importance of BN substrate interaction for h-BN to act as the ORR electrocatalyst. A possible role of the edge of the BN islands for ORR is also discussed.
  • Min Gao, Andrey Lyalin, Satoshi Maeda, Tetsuya Taketsugu
    JOURNAL OF CHEMICAL THEORY AND COMPUTATION 10 (4) 1623 - 1630 1549-9618 2014/04 [Refereed][Not invited]
     
    A new theoretical approach to find metal-cluster-catalyzed single bond activation pathways is introduced. The proposed approach combines two automated reaction path search techniques: the anharmonic downward distortion following (ADDF) and the artificial force induced reaction (AFIR) methods, developed in our previous works [Maeda, S.; Ohno, K.; Morokuma, K. Phys. Chem. Chem. Phys. 2013, IS, 3683-3701]. A simple model reaction of the H-H bond activation catalyzed by Au-n (n = 7,8) clusters is considered as an example. We have automatically found 33 and 20 transition-state (TS) structures for H-2 dissociation on Au-7 and Au-8 clusters, respectively, and successfully identified the best dissociation pathways with the lowest barrier. Systematic analysis of the structure-dependent reactivity of small gold clusters is performed. It is demonstrated that the most stable structures of the gold clusters are not always highly reactive and several isomeric structures must be taken into account for adequate description of the reaction rates at finite temperatures. The proposed approach can serve as a promising tool for investigation of the chemical reactions catalyzed by small metal clusters.
  • Andrey Lyalin, Akira Nakayama, Kohei Uosaki, Tetsuya Taketsugu
    JOURNAL OF PHYSICAL CHEMISTRY C 117 (41) 21359 - 21370 1932-7447 2013/10 [Refereed][Not invited]
     
    The catalytic activity for the oxygen reduction reaction (ORR) of a hexagonal boron nitride (h-BN) monolayer supported on a Ni(111) surface has been studied theoretically using density-functional theory. It is shown that the Ni(111) support can critically change the chemical and physical properties of defect-free monolayer h-BN, considerably promoting the adsorption of O-2, OOH, OH, and O species, and therefore, it is demonstrated that inert defect-free monolayer h-BN can be functionalized by the metal support and become catalytically active for the ORR. Although simple potential-dependent modeling of the energetics of the ORR on h-BN/Ni(111) indicates the limitation of the ORR process due to the large overpotential, our calculations demonstrate the ability to fiinctionalize inert materials for the ORR and open new ways to design effective Pt-free catalysts for fuel-cell technology.
  • Min Gao, Andrey Lyalin, Tetsuya Taketsugu
    INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY 113 (4) 443 - 452 0020-7608 2013/02 [Refereed][Not invited]
     
    Molecular and dissociative adsorption of O2 on Au atoms supported on the regular and defected hexagonal boron nitride (h-BN) surface has been studied theoretically using density functional theory. It is shown that even weak interaction of Au with the defect-free h-BN support has an unusually strong influence on the binding and catalytic activation of the molecular oxygen. The strong interaction of Au with vacancy point defects on the h-BN surface is accompanied by the large charge transfer to/from the adsorbate which can considerably affect the catalytic activity of the supported Au. It is demonstrated that activation of the molecular O2 and barriers for O2 dissociation on the supported Au atom can be affected by the interaction of Au with the pristine or defected h-BN support. Therefore, the h-BN surface cannot be considered as an absolutely inert support for Au. (C) 2012 Wiley Periodicals, Inc.
  • Min Gao, Andrey Lyalin, Tetsuya Taketsugu
    Journal of Chemical Physics 138 (3) 034701  0021-9606 2013/01/21 [Refereed][Not invited]
     
    The mechanism of CO oxidation by O2 on Au atoms supported on the pristine and defected hexagonal boron nitride (h-BN) surface has been studied theoretically using density functional theory. It is found that O2 binds stronger than CO on an Au atom supported on the defect free h-BN surface and h-BN surface with nitrogen vacancy (VN@h-BN), but weaker than CO on a free Au atom or Au trapped by a boron vacancy (VB@h-BN). The excess of the positive or negative charge on Au can considerably change its catalytic properties and enhance activation of the adsorbed O2. Coadsorption of CO and O2 on Au, Au/VN@h-BN, and Au/V B@h-BN results in additional charge transfer to O2. Various pathways of the CO oxidation reaction by molecular oxygen are studied. We found two different pathways for CO oxidation: a two-step pathway where two CO2 molecules are formed independently, and a self-promotion pathway where oxidation of the first CO molecule is promoted by the second CO molecule. Interaction of Au with the defect-free and defected h-BN surface considerably affects the CO oxidation reaction pathways and barriers. Therefore, Au supported on the h-BN surface (pristine or defected) cannot be considered as pseudo-free atom and support effects have to be taken into account, even when the interaction of Au with the support is weak. © 2013 American Institute of Physics.
  • Min Gao, Andrey Lyalin, Tetsuya Taketsugu
    Journal of Physics: Conference Series 438 (1) 1742-6596 2013 [Refereed][Not invited]
     
    The mechanism of CO oxidation by O2 on Au atoms supported on the pristine and defected hexagonal boron nitride (h-BN) surface has been studied theoretically using density functional theory. Two possible routes for catalytic oxidation are considered. The first route consists in a preliminary dissociation of the adsorbed O2 followed by consequential oxidation of a reactant molecule by atomic oxygen. Although the presence of h-BN surface can change the O2 dissociation barrier, it remains relatively high. The second route is a direct oxidation reaction between the activated molecular oxygen and the reactant. We have found two different pathways for CO oxidation: a two-step pathway where two CO2 molecules are formed independently, and a self-promotion pathway where oxidation of the first CO molecule is promoted by the second CO molecule. Interaction of Au with the defect-free and defected h-BN surface considerably affects the CO oxidation reaction pathways and barriers. Therefore, Au supported on the h-BN surface (pristine or defected) cannot be considered as pseudo-free atom and support effects have to be taken into account, even when the interaction of Au with the support is weak.
  • Andrey Lyalin, Akira Nakayama, Kohei Uosaki, Tetsuya Taketsugu
    PHYSICAL CHEMISTRY CHEMICAL PHYSICS 15 (8) 2809 - 2820 1463-9076 2013 [Refereed][Not invited]
     
    The catalytic activity for the oxygen reduction reaction (ORR) of both the pristine and defect-possessing hexagonal boron nitride (h-BN) monolayer and H-terminated nanoribbon have been studied theoretically using density functional theory. It is demonstrated that an inert h-BN monolayer can be functionalized and become catalytically active by nitrogen doping. It is shown that the energetics of adsorption of O-2, O, OH, OOH, and H2O on N atom impurities in the h-BN monolayer (N-B@h-BN) is quite similar to that known for a Pt(111) surface. The specific mechanism of destructive and cooperative adsorption of ORR intermediates on the surface point defects is discussed. It is demonstrated that accounting for entropy and zero-point energy (ZPE) corrections results in destabilization of the ORR intermediates adsorbed on N-B@h-BN, while solvent effects lead to their stabilization. Therefore, entropy, ZPE and solvent effects partly cancel each other and have to be taken into account simultaneously. Analysis of the free energy changes along the ORR pathway allows us to suggest that a N-doped h-BN monolayer can demonstrate catalytic properties for the ORR under the condition that electron transport to the catalytically active center is provided.
  • Min Gao, Andrey Lyalin, Tetsuya Taketsugu
    JOURNAL OF PHYSICAL CHEMISTRY C 116 (16) 9054 - 9062 1932-7447 2012/04 [Refereed][Not invited]
     
    The structural, electronic, and catalytic properties of Au and Au-2 supported on the pristine and defected hexagonal boron nitride (h-BN) surface have been studied theoretically using density functional theory. It is demonstrated that adsorption and catalytic activation of O-2 on the h-BN supported Au and Au-2 can be affected by the interaction with the support via electron pushing and donor/acceptor mechanisms. It is shown that even weak interaction of Au and Au-2 with the defect-free "inert" h-BN surface can have an unusually strong influence on the binding and catalytic activation of the molecular oxygen. This effect occurs due to the mixing of the 5d orbitals of the supported Au and Au-2 with the N-p(z) orbitals. Although the defect-free h-BN surface does not act as a good electron donor for the supported O-2-Au, it promotes an electron transfer from the Au to O-2, pushing electrons from the gold to the adsorbed oxygen. In the case of the defected h-BN surface, Au and Au-2 can be trapped effectively by N or B vacancy and impurity point defects. Strong adsorption on the surface defects is accompanied by the large charge transfer to/from the adsorbate. The excess of the positive or negative charge on the supported Au and Au-2 can considerably promote their catalytic activity. Therefore, the h-BN surface (pristine or defected) cannot be considered as an inert support for Au and Au-2.
  • Min Gao, Andrey Lyalin, Tetsuya Taketsugu
    CATALYSTS 1 (1) 18 - 39 2073-4344 2011/12 [Refereed][Not invited]
     
    It is demonstrated that the support effects play a crucial role in the gold nanocatalysis. Two types of support are considered-the "inert" support of hexagonal boron nitride (h-BN) with the N and B vacancy defects and the "active" support of rutile TiO2(110). It is demonstrated that Au and Au-2 can be trapped effectively by the vacancy defects in h-BN. In that case, the strong adsorption on the surface defects is accompanied by the charge transfer to/from the adsorbate. The excess of the positive or negative charge on the supported gold clusters can considerably promote their catalytic activity. Therefore gold clusters supported on the defected h-BN surface can not be considered as pseudo-free clusters. We also demonstrate that the rutile TiO2(110) support energetically promotes H-2 dissociation on gold clusters. We show that the formation of the OH group near the supported gold cluster is an important condition for H-2 dissociation. We demonstrate that the active sites towards H-2 dissociation on the supported Au-n are located at corners and edges of the gold cluster in the vicinity of the low coordinated oxygen atoms on TiO2(110). Thus catalytic activity of a gold nanoparticle supported on the rutile TiO2(110) surface is proportional to the length of the perimeter interface between the nanoparticle and the support.
  • Andrey Lyalin, Tetsuya Taketsugu
    FARADAY DISCUSSIONS 152 185 - 201 1359-6640 2011 [Refereed][Not invited]
     
    The specific role played by small gold nanoparticles supported on the rutile TiO2(110) surface in the processes of adsorption and dissociation of H-2 is discussed. It is demonstrated that the molecular and dissociative adsorption of H-2 on Lambda u(n) clusters containing n = 1, 2, 8 and 20 atoms depends on cluster size, geometry structure, cluster flexibility and the interaction with the support material. Rutile TiO2(110) support energetically promotes H-2 dissociation on gold clusters. It is demonstrated that the active sites towards H-2 dissociation are located at corners and edges on the surface of the gold nanoparticle in the vicinity of the support. The low coordinated oxygen atoms on the TiO2(110) surface play a crucial role for H-2 dissociation. Therefore the catalytic activity of a gold nanoparticle supported on the rutile TiO2(110) surface is proportional to the length of the perimeter interface between the nanoparticle and the support.
  • Andrey Lyalin, Tetsuya Taketsugu
    JOURNAL OF PHYSICAL CHEMISTRY LETTERS 1 (12) 1752 - 1757 1948-7185 2010/06 [Refereed][Not invited]
     
    The molecular and dissociative adorption of O-2 on pure odd-size Au-n, (n = 1,3,5,7,9) clusters and Au-n with a coadsorbed C2H4 molecule has been studied theoretically using density functional theory. It is demonstrated that catalytic activation of the adsorbed O-2 on pure gold clusters in the considered size range cannot lead to O-2 dissociation. Coadsorption of C2H4, however, involves an extra charge transfer from the gold cluster to O-2 energetically promoting oxygen dissociation. Our finding indicates that O-2 dissociation on the surface of small gold clusters in sensitive to the presence of other adsorbates, including the reactant molecule itself. This effect can be particularly important for understanding the mechanism of catalytic oxidation on gold clusters.
  • Andrey Lyalin, Tetsuya Taketsugu
    JOURNAL OF PHYSICAL CHEMISTRY C 114 (6) 2484 - 2493 1932-7447 2010/02 [Refereed][Not invited]
     
    The adsorption of ethylene molecules on neutral, anionic, and cationic gold clusters consisting of up to 10 atoms has been investigated using density functional theory. It is demonstrated that C(2)H(4) can be adsorbed on small gold clusters in two different configurations, corresponding to the pi- and di-sigma-bonded species. Adsorption in the pi-bonded mode dominates over the di-sigma mode over all considered cluster sizes n, with the exception of the neutral C(2)H(4)-Au(5) system. A striking difference is found in the size dependence of the adsorption energy Of C(2)H(4) bonded to the neutral gold clusters in the pi and di-sigma configurations. The important role of the electronic shell effects in the di-sigma mode of ethylene adsorption on neutral gold Clusters is demonstrated. It is shown that the interaction of C(2)H(4) with small gold clusters strongly depends on their charge. The typical shift in the vibrational frequencies of C(2)H(4) adsorbed in the pi and the di-sigma configurations gives a guidance to experimentally distinguish between the two modes of adsorption.
  • Andrey Lyalin, Tetsuya Taketsugu
    JOURNAL OF PHYSICAL CHEMISTRY C 113 (30) 12930 - 12934 1932-7447 2009/07 [Refereed][Not invited]
     
    The adsorption Of O-2 and C2H4 molecules on small gold clusters consisting of up to 10 atoms has been investigated using theoretical methods based on density-functional theory. It is shown that, in addition to a conventional mechanism of the catalytic activation Of O-2 adsorbed oil a gold cluster, the interaction Of C2H4 with small gold clusters results in considerable weakening of the carbon-carbon double bond. Moreover, coadsorption Of O-2 and C2H4 on small gold clusters with an odd number of atoms leads to cooperative effect which further stabilizes the O-2-Au-N-C2H4 system. Hence, Simultaneous adsorption of the O-2 and C2H4 molecules on free gold clusters can considerably promote the oxidation process via the Langmuir-Hinshelwood mechanism.
  • Andrey Lyalin, Adilah Hussien, Andrey V. Solov'yov, Walter Greiner
    PHYSICAL REVIEW B 79 (16) 2469-9950 2009/04 [Refereed][Not invited]
     
    We demonstrate that the addition of a carbon impurity leads to significant changes in the thermodynamic properties of a Ni-147 cluster. The magnitude of the change induced is dependent on the parameters of the Ni-C interaction. Hence, thermodynamic properties of Ni clusters can be effectively tuned by the addition of a particular type of impurity. We also show that the presence of a carbon impurity considerably changes the mobility and diffusion of atoms in the Ni cluster at temperatures close to its melting point. The calculated diffusion coefficients of the carbon impurity in the Ni cluster can be used as a reliable estimate of the growth rate of carbon nanotubes.
  • Andrey Lyalin, Tetsuya Taketsugu
    AIP Conference Proceedings {AIP} Publishing 1197 (1) 65  2009 [Refereed][Not invited]
  • PETER BERKE, MARIE-PAULE DELPLANCKE-OGLETREE, ANDREY LYALIN, VERONIKA V, SEMENIKHINA, ANDREY V. SOLOV{\textquotesingle}YOV
    Latest Advances in Atomic Cluster Collisions World Scientific Pub Co Pte Lt 205 - 224 2008/09 [Refereed][Not invited]
  • Andrey Lyalin, Adilah Hussien, Andrey V. Solov'yov, Walter Greiner
    Phys. Rev. B 79, 165403, (2009) 2008/08/09 [Not refereed][Not invited]
     
    We demonstrate that the addition of a single carbon impurity leads to
    significant changes in the thermodynamic properties of Ni clusters consisting
    of more than a hundred atoms. The magnitude of the change induced is dependent
    upon the parameters of the Ni-C interaction. Hence, thermodynamic properties of
    Ni clusters can be effectively tuned by the addition of an impurity of a
    particular type. We also show that the presence of a carbon impurity
    considerably changes the mobility and diffusion of atoms in the Ni cluster at
    temperatures close to its melting point. The calculated diffusion coef...
  • V. V. Semenikhina, A. G. Lyalin, A. V. Solov'yov, W. Greiner
    JOURNAL OF EXPERIMENTAL AND THEORETICAL PHYSICS 106 (4) 678 - 689 1063-7761 2008/04 [Refereed][Not invited]
     
    A method for calculating the characteristics of the stability, energy, and geometry of an atomic cluster at a solid surface is proposed, which is based on a droplet model that takes into account the cluster-solid interaction. As an example, the interaction of a neutral argon cluster with a (001) surface of graphite is considered. The results of calculations performed within the framework of the droplet model show good agreement with the results of numerical simulation based on a dynamic search for the most stable isomers in the course of cluster growth. It is shown that the droplet model can be used for simple evaluation of the geometry, stability, and energy characteristics of clusters at solid surfaces.
  • Lyalin A, Solov?Yov A.V, Greiner W
    Latest Advances in Atomic Cluster Collisions: Structure and Dynamics from the Nuclear to the Biological Scale 105 - 127 2008 [Refereed][Not invited]
  • Lyalin A, Solov?Yov A.V, Greiner W
    Latest Advances in Atomic Cluster Collisions: Structure and Dynamics from the Nuclear to the Biological Scale 86 - 104 2008 [Refereed][Not invited]
  • Andrey Lyalin, Ilia A. Solov'yov, Andrey V. Solov'yov, Walter Greiner
    PHYSICAL REVIEW A 75 (5) 053201  1050-2947 2007/05 [Refereed][Not invited]
     
    The optimized structure and electronic properties of neutral, singly, and doubly charged strontium clusters have been investigated using ab initio theoretical methods based on density-functional theory. We have systematically calculated the optimized geometries of neutral, singly, and doubly charged strontium clusters consisting of up to 14 atoms, average bonding distances, electronic shell closures, binding energies per atom, the gap between the highest occupied and the lowest unoccupied molecular orbitals, and spectra of the density of electronic states (DOS). It is demonstrated that the size evolution of structural and electronic properties of strontium clusters is governed by an interplay of the electronic and geometry shell closures. Influence of the electronic shell effects on structural rearrangements can lead to violation of the icosahedral growth motif of strontium clusters. It is shown that the excessive charge essentially affects the optimized geometry of strontium clusters. Ionization of small strontium clusters results in the alteration of the magic numbers. The strong dependence of the DOS spectra on details of ionic structure allows one to perform a reliable geometry identification of strontium clusters.
  • A. G. Lyalin, O. I. Obolensky, A. V. Solov'Yov, W. Greiner
    ROMANIAN REPORTS IN PHYSICS 59 (2) 499 - 513 1221-1451 2007 [Refereed][Not invited]
     
    Advances achieved during recent years in model and ab initio descriptions of fission of atomic clusters are reviewed. We focus on developments in ab initio treatment of the electronic subsystem within the jellium background model, as well as on applications of potential energy surface analysis to determining the characteristics of the fission process. We reiterate the main results obtained with the implementation of the Hartree-Fock and local density schemes for the two-center deformed jellium model.
  • Andrey Lyalin, Andrey V. Solov'yov, Walter Greiner
    PHYSICAL REVIEW A 74 (4) 043201  1050-2947 2006/10 [Refereed][Not invited]
     
    The optimized structure, electronic and magnetic properties of La clusters consisting of up to 14 atoms have been investigated using ab initio theoretical methods based on density-functional theory. Structural and spin isomers have been determined. We show that increase in cluster symmetry can promote ferromagnetic instability in La clusters. A giant enhancement of magnetism in La-4, La-6, and La-13 clusters is predicted. We also found that the ground states of La-2, La-3, La-5, La-7, La-9-La-11, and La-14 clusters possess nonzero magnetic moments, that ranged from similar to 0.1 mu(B) to 1.0 mu(B) per atom. Strong dependence of the magnetic moment on temperature for T > 300 K is predicted. The results obtained are compared with the available experimental data and the results of other theoretical works.
  • A. G. Lyalin, A. V. Solov'yov
    RADIATION PHYSICS AND CHEMISTRY 75 (10) 1358 - 1379 0969-806X 2006/10 [Refereed][Not invited]
     
    We consider a photon emission in collisions of electrons with atomic clusters under conditions in which the radiation of atomic electrons is significant or even dominates the total spectrum. This occurs for example, when the frequency of the emitted photon is comparable with the energy of a plasmon resonance in a cluster. We consider general results of the theory of polarizational bremsstrahlung, and we present the results of recent calculations of the cross sections of this process for a number of targets. (C) 2006 Elsevier Ltd. All rights reserved.
  • A Lyalin, OI Obolensky, AV Solov'Yov, W Greiner
    INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS 15 (1) 153 - 195 0218-3013 2006/02 [Refereed][Not invited]
     
    Advances achieved during recent years in model and ab initio descriptions of fission of metal clusters are reviewed, We focus on developments in ab initio treatment of he electronic subsystem within the jellium background model, as well as on applications of potential energy surface analysis to determining the characteristics of the fission process. We reiterate the main results obtained with the implementation of the Hartree-Fock and local density schemes for the two-center deformed jellium model. We overview the influences of the geometrical and statistical factors on the parameters of the fission process revealed recently. Also, we overview concisely the classical liquid drop model, the shell correction method, the asymmetric two-center-oscillator shell model, and the main approaches to the molecular dynamics simulations of the fission process.
  • OI Obolensky, AG Lyalin, AV Solov'yov, W Greiner
    PHYSICAL REVIEW B 72 (8) 085433  2469-9950 2005/08 [Refereed][Not invited]
     
    Fission of metastable charged univalent metal clusters has been studied on examples of Na-10(2+) and Na-18(2+) clusters by means of density functional theory methods. Energetics of the process, i.e., dissociation energies and fission barriers, as well as its dynamics, i.e., fission pathways, have been analyzed. The dissociation energies and fission barriers have been calculated for the full range of fission channels for the Na-10(2+) cluster. Our data confirm the viewpoint that there is some correlation between these two quantities, which can often be explained by electronic shell effects. However, there is no quantitative correspondence between the dissociation energies and heights of fission barriers and the former cannot serve as a quick estimate for the latter. The impact of cluster structure on the fission process has been elucidated. The calculations show that the geometry of the smaller fragment and the geometry of its immediate neighborhood in the larger fragment play a leading role in defining the fission barrier height: energy barriers for removing different combinations of atoms from the same parent cluster can vary greatly, while energy barriers for removing similar groups of atoms from similar places in different isomers of the parent cluster are usually similar. The present study demonstrates the importance of rearrangement of the cluster structure during fission. The rearrangement can lower the fission barriers significantly. It may include forming a neck between the two fragments or fissioning via another isomer state of the parent cluster; examples of such processes are given. For several low-lying isomers of the Na-10(2+) cluster the potential barriers for transitions between these isomer states are calculated and compared with the corresponding fission barriers. These data suggest that there is a competition between "direct" fission and fission going via formation of intermediate isomer states of the parent cluster. An impact of the cluster geometry on the change of the system's entropy due to fission is also discussed.
  • A Lyalin, OI Obolensky, AV Solov'yov, W Greiner
    EUROPEAN PHYSICAL JOURNAL D 34 (1-3) 93 - 96 1434-6060 2005/07 [Refereed][Not invited]
     
    Fission of charged small sodium and strontium clusters has been studied by the ab initio density functional theory methods. Dissociation energies and fission barriers have been calculated for all possible fission channels for the Na-10(2+) and Sr-7(2+) clusters. The dissociation energies and fission barriers have been analyzed as functions of the daughter fragment size.
  • A Lyalin, AV Solov'yov, C Brechignac, W Greiner
    JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS 38 (10) L129 - L135 0953-4075 2005/05 [Refereed][Not invited]
     
    Dissociation and fission of small neutral, singly and doubly charged strontium clusters are studied by means of ab initio density functional theory methods and high-resolution time-of-flight mass spectrometry. Magic numbers for small strontium clusters possessing enhanced stability towards monomer evaporation and fission are determined. It is shown that ionization of small strontium clusters results in the alteration of the magic numbers. Thermal promotion of Coulombic fission for the Sr-7(2+) cluster is predicted.
  • Andrey Lyalin, Oleg Obolensky, Ilia A. Solov{\textquotesingle}yov, Andrey V. Solov, yo, Walter Greiner
    Latest Advances in Atomic Cluster Collisions World Scientific Pub Co Pte Lt 157  2004/11 [Refereed][Not invited]
  • Ilia A. Solov{\tex, quotesingle}yov, Andrey Lyalin, Andrey V. Solov, yo, Walter Greiner
    Latest Advances in Atomic Cluster Collisions World Scientific Pub Co Pte Lt 51  2004/11 [Refereed][Not invited]
  • A. G. Lyalin, O. I. Obolensky, Il. A. Solov'yov, A. V. Solov'yov, W. Greiner
    PHYSICA SCRIPTA T110 319 - 324 0031-8949 2004 [Refereed][Not invited]
     
    Results of molecular dynamics simulations of fission reactions Na-10(2+) -> Na-7(+) + Na-3(+) and Na-18(2+) -> 2Na(9)(+) are presented. The dependence of the fission barriers on the isomer structure of the parent cluster is analyzed. It is demonstrated that the energy necessary for removing homothetic groups of atoms from the parent cluster is largely independent of the isomer form of the parent cluster. The importance of rearrangement of the cluster structure during the fission process is elucidated. This rearrangement may include transition to another isomer state of the parent cluster before actual separation of the daughter fragments begins and/or forming a "neck'' between the separating fragments. A novel algorithm for modeling the cluster growth process is described. This approach is based on dynamic search for the most stable cluster isomers and allows one to find the optimized cluster geometries, as well as their essential formation mechanisms. Cluster growth paths for Lennard-Jones clusters have been investigated for cluster sizes of up to 150 atoms. All known global minima structures of the Lennard-Jones clusters are found.
  • AG Lyalin, OI Obolensky, AV Solov'yov, IA Solov'yov, W Greiner
    JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS 37 (1) L7 - L13 0953-4075 2004/01 [Refereed][Not invited]
     
    Results of molecular dynamics simulations of fission reactions Na-10(2+) --> Na-7(+) + Na-3(+) and Na-18(2+) --> 2Na(9)(+) are presented. The dependence of the fission barriers on the isomer structure of the parent cluster is analysed. It is demonstrated that the energy necessary for removing homothetic groups of atoms from the parent cluster is largely independent of the isomer form of the parent cluster. The importance of rearrangement of the cluster structure during the fission process is elucidated. This rearrangement may include transition to another isomer state of the parent cluster before actual separation of the daughter fragments begins and/or forming a 'neck' between the separating fragments.
  • A Lyalin, IA Solov'yov, AV Solov'yov, W Greiner
    PHYSICAL REVIEW A 67 (6) 632031 - 6320313 1050-2947 2003/06 [Refereed][Not invited]
     
    The optimized structure and electronic properties of neutral and singly charged magnesium clusters have been investigated using ab initio theoretical methods based on density-functional theory and systematic post-Hartree-Fock many-body perturbation theory accounting for all electrons in the system. We have systematically calculated the optimized geometries of neutral and singly charged magnesium clusters consisting of up to 21 atoms, electronic shell closures, binding energies per atom, ionization potentials, and the gap between the highest occupied and the lowest unoccupied molecular orbitals. We have investigated the appearance of the elements of the hcp structure and metallic evolution of the magnesium clusters, as well as the stability of linear chains and rings of magnesium atoms. The results obtained are compared with the available experimental data and the results of other theoretical works.
  • A Lyalin, A Matveentsev, IA Solov'yov, AV Solov'yov, W Greiner
    EUROPEAN PHYSICAL JOURNAL D 24 (1-3) 15 - 18 1434-6060 2003/06 [Refereed][Not invited]
     
    This work is devoted to the elucidation the applicability of jellium model to the description of alkali cluster properties on the basis of comparison the jellium model results with those derived from experiment and within ab initio theoretical framework. On the basis of the Hartree-Fock and local-density approximation deformed jellium model we have calculated the binding energies per atom, ionization potentials, deformation parameters and the optimized values of the Wigner-Seitz radii for neutral and singly charged sodium clusters with the number of atoms N less than or equal to 20. These characteristics are compared with the results derived from the ab initio all-electron simulations of cluster electronic and ionic structure based on the density functional theory as well as on the post Hartree-Fock perturbation theory on many-electron correlation interaction. The comparison performed demonstrates the great role of cluster shape deformations in the formation cluster properties and the quite reasonable level of applicability of the deformed jellium model.
  • ANTON MATVEENTSEV, ANDREY LYALIN, ILIA A. SOLOV{\textquotesingle}YOV, ANDREY V. SOLOV{\textquotesingle}YOV, WALTER GREINER
    Int. J. Mod. Phys. E World Scientific Pub Co Pte Lt 12 (01) 81  2003/02 [Refereed][Not invited]
  • A Matveentsev, A Lyalin, IA Solov'yov, AV Solov'yov, W Greiner
    INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS 12 (1) 81 - 107 0218-3013 2003/02 [Refereed][Not invited]
     
    This work is devoted to the elucidation of the applicability of the jellium model to the description of alkali cluster properties. We compare the jellium model results with those derived within ab initio theoretical approaches and with experiments. On the basis of Hartree-Fock and local-density approximations we have calculated the binding energies per atom, ionization potentials, deformation parameters and optimized values of the Wigner-Seitz radii for neutral and singly charged sodium clusters with the number of atoms N less than or equal to 20. The characteristics calculated within the framework of the deformed jellium model are compared with the results derived from ab initio simulations of cluster electronic and ionic structure based on density functional theory and systematic post Hartree-Fock many-body perturbation theory accounting for all electrons in the system. The comparison performed demonstrates the great role of the cluster shape deformations in the formation cluster properties and quite reasonable level of applicability of the deformed jellium model. This elucidates the similarities of atomic cluster physics with the physics of atomic nuclei.
  • AG Lyalin, AV Solov'yov, W Greiner, OI Obolensky
    PROCEEDINGS OF THE THIRD INTERNATIONAL CONFERENCE FISSION AND PROPERTIES OF NEUTRON-RICH NUCLEI 472 - 479 2003 [Refereed][Not invited]
     
    Fission of doubly charged metal clusters is studied using the open-shell two-center deformed jellium Hartree-Fock and local density approximations as well as within ab initio molecular dynamic approach accounting for all electrons in the system. Results of calculations of the fission barriers for the symmetric and asymmetric fission processes Na-10(2+) -> Na-7(+) + Na-3(+), Na-18(2+) -> Na-15(+) + Na-3(+) and Na-18(2+) -> 2Na(9)(+) are presented. The role of exchange and many-electron correlation effects in metal clusters fission is analyzed. It is demonstrated that the influence of many-electron correlations on the height of the fission barrier is more profound if the barrier arises nearby or beyond the scission point. The importance of cluster deformations in the fission process is elucidated with the use of the overlapping-spheroids shape parameterization allowing one an independent variation of deformations in the parent and daughter clusters.
  • A Lyalin, A Solov'yov, W Greiner
    PHYSICAL REVIEW A 65 (4) 2469-9926 2002/04 [Refereed][Not invited]
     
    Fission of doubly charged metal clusters is studied using the open-shell two-center deformed jellium Hartree-Fock model and local density approximation. Results of calculations of the electronic structure and fission barriers for the symmetric and asymmetric channels associated with the following processes Na-10(2+)-->Na7+Na3+, Na-18(2+)-->Na-15(+)+Na-3(+) and Na-18(2+)-->2Na(9)(+) are presented. The role of the exact exchange and many-body correlation effects in metal clusters fission is analyzed. It is demonstrated that the influence of many-electron correlation effects on the height of the fission barrier is more profound if the barrier arises nearby or beyond the scission point. The importance of cluster deformation effects in the fission process is elucidated with the use of the overlapping-spheroids shape parametrization allowing one an independent variation of deformations in the parent and daughter clusters.
  • AV Korol, AG Lyalin, AV Solovy'ov, NB Avdonina, RH Pratt
    JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS 35 (5) 1197 - 1210 0953-4075 2002/03 [Refereed][Not invited]
     
    We discuss two different approaches for the approximate treatment of the bremsstrahlung (BrS) process of non-relativistic electrons on many-electron atomic/ionic targets, described by a total amplitude which is a sum of ordinary and polarizational BrS amplitudes. The approaches are based on the so-called 'stripping' effect; they are useful for calculation of the BrS spectra for photon energies greater than the outer shell thresholds.
  • A Lyalin, A Solov'yov, W Greiner, S Semenov
    PHYSICAL REVIEW A 65 (2) 023201/1-023201/5 - 5 1050-2947 2002/02 [Refereed][Not invited]
     
    Fission of doubly charged metal clusters is studied using the open-shell two-center jellium Hartree-Fock approximation. Two-overlapping-spheroids shape parametrization allows one to obtain independent variation of deformations in the parent and daughter clusters. Results of calculations of the electronic structure and fission barriers for the symmetric channel associated with the process Na-18(2+)-->2Na(9)(+) are presented. The importance of cluster-deformation effects in the fission process is reported. The model developed forms the basis for the systematic many-body theory of metal-cluster-fission phenomena.
  • AV Korol, AG Lyalin, OI Obolensky, AV Solovyov, IA Solovjev
    JOURNAL OF EXPERIMENTAL AND THEORETICAL PHYSICS 94 (4) 704 - 719 1063-7761 2002 [Refereed][Not invited]
     
    A completely relativistic mechanism for describing polarization bremsstrahlung caused by an elastic collision of a charged particle with a many-electron target was suggested. Multipole expansions for the amplitude and cross section of the process taking into account radiation lag effects were obtained. Including higher order multipoles was shown to result in substantial asymmetry of the angular distribution of emitted photons compared with the dipole case and in a noticeable change in the spectral characteristics of polarization radiation. The cross section of polarization bremsstrahlung was found to increase logarithmically as the energy of incident particles grew. (C) 2002 MAIK "Nauka / Interperiodica".
  • Andrey Lyalin, Andrey Solov'yov, Walter Greiner
    Phys. Rev. A 65, 043202, (2002) 2001/12/05 [Not refereed][Not invited]
     
    Fission of doubly charged metal clusters is studied using the open-shell
    two-center deformed jellium Hartree-Fock model and Local Density Approximation.
    Results of calculations of the electronic structure and fission barriers for
    the symmetric and asymmetric channels associated with the following processes
    Na_{10}^{2+} --> Na_{7}^{+} + Na_{3}^{+}, Na_{18}^{2+} --> Na_{15}^{+} +
    Na_{3}^{+} and Na_{18}^{2+} --> 2 Na_{9}^{+} are presented. The role of the
    exact exchange and many-body correlation effects in metal clusters fission is
    analysed. It is demonstrated that the influence of many-electr...
  • A Lyalin, S Semenov, A Solov'yov, N Cherepkov, JP Connerade, W Greiner
    JOURNAL OF THE CHINESE CHEMICAL SOCIETY 48 (3) 419 - 426 0009-4536 2001/06 [Refereed][Not invited]
     
    We have developed the Hartree-Fock jellium model for deformed metal clusters by treating the quantized electron motion in the field of the spheroidal ionic jellium background in the Hartree-Fock approximation. Using this model, we have calculated single electron energy levels as a function of the cluster deformation parameter for a series of sodium clusters with the number of atoms N in a cluster ranging from 4 to 40. We have established that the cluster deformations corresponding to the minimum total energy of the oblate and prolate clusters are in reasonable agreement with the experimental data and the predictions of other theoretical models.
  • JP Connerade, AG Lyalin, R Semaoune, SK Semenov, AV Solov'yov
    JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS 34 (12) 2505 - 2511 0953-4075 2001/06 [Refereed][Not invited]
     
    We present a new theoretical method for the calculation of the electronic structure of the hydrogen atom confined inside a prolate-shaped C-60 fullerene cage. The method is based on solving the one-electron Schrodinger equation written in the prolate-spheroidal-coordinate system and using the quasi-atom concept for modelling the effects of the deformed endohedral environment. The energy levels of H@C-60 are qualitatively studied as a function of the deformation parameter delta. Avoided crossing points between levels of the same symmetry are revealed.
  • AG Lyalin, S Semenov, AV Solov'yov, NA Cherepkov, W Greiner
    JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS 33 (18) 3653 - 3664 0953-4075 2000/09 [Refereed][Not invited]
     
    We have developed the Hartree-Fock jellium model for deformed metal clusters, which treats the quantized electron motion in the field of the spheroidal ionic jellium background in the Hartree-Fock approximation. Using this model, we have calculated single electron energy levels as a function of the cluster deformation parameter for a series of sodium clusters with the number of atoms N in a cluster ranging from 4 to 40. We have established that the cluster deformations corresponding to the minimum total energy of the oblate and prolate clusters are in a reasonable agreement with the experimental data and predictions of other theoretical models.
  • A.V. Korol, A.G. Lyalin, O.I. Obolensky, A.V. Solov'yov
    Journal of Physics B: Atomic, Molecular and Optical Physics 33 (5) L179-L186 - L186 2000 [Refereed][Not invited]
  • AV Korol', AG Lyalin, AV Solov'ev
    OPTICS AND SPECTROSCOPY 86 (4) 486 - 492 0030-400X 1999/04 [Refereed][Not invited]
     
    An efficient method for calculating the cross section for bremsstrahlung with the polarization mechanism taken into account is developed. Cross sections for bremsstrahlung are calculated for collisions of electrons with energies of 1-25 keV with Kr atoms in the region of photon frequencies from 10 eV up to the shortwavelength boundary of the spectrum. An important role of the mechanism of polarization bremsstrahlung in the formation of the total radiation spectrum over the entire frequency range is demonstrated. The atomic system of units (\e\ = (h) over bar = m(e) = 1) is used in the work.
  • AV Korol, AG Lyalin, OI Obolenskii, AV Solov'ev
    JOURNAL OF EXPERIMENTAL AND THEORETICAL PHYSICS 87 (2) 251 - 259 1063-7761 1998/08 [Refereed][Not invited]
     
    This paper develops an effective method for calculating the bremsstrahlung cross section with allowance for the polarization mechanism. We calculate the cross section of bremsstrahlung produced in the scattering of electrons and positrons by H and Kr atoms. We also demonstrate the important role of polarization bremsstrahlung in the formation of the total emission spectrum over the entire frequency range. (C) 1998 American Institute of Physics. [S1063-7761(98)00708-2].
  • LG Gerchikov, AV Korol, AG Lyalin, AV Solovyov
    X-RAY AND INNER-SHELL PROCESSES - 17TH INTERNATIONAL CONFERENCE (389) 447 - 463 0094-243X 1997 [Refereed][Not invited]
     
    We consider a photon emission in collisions of electrons with atoms and clusters under the conditions when the radiation of atomic electrons gives significant or even dominating contribution to the total spectrum. This occurs, for example, when the frequency of the emitted photon is comparable with the energy of giant collective or plasmon resonance in an atom or cluster. We consider the manifestation of the effect for atomic and solid targets demonstrating the significant role of the photon self-absorption and electron energy loss in a solid target. We present results of recent calculations of the cross sections of the process for a number of targets. Theoretical results are compared with the available experimental data.
  • A.V. Korol, A.G. Lyalin, A.V. Solovy'ov
    Journal of Physics B: Atomic, Molecular and Optical Physics 30 (4) L115-L121 - L121 1997 [Refereed][Not invited]
  • AV Korol, AG Lyalin, AS Shulakov, AV Solovyov
    JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA 79 323 - 326 0368-2048 1996/05 [Refereed][Not invited]
     
    Bremsstrahlung (BrS) spectra for a 0.2-10 keV electron on Ba, La and Eu are calculated for the photon energies above the 4d-threshold: omega = 100 - 200 eV. The polarizational BrS is taken into account. A simple method is proposed for the approximate calculation of the polarizational BrS cross section.
  • AV Korol, AG Lyalin, AV Solovev, AS Shulakov
    ZHURNAL EKSPERIMENTALNOI I TEORETICHESKOI FIZIKI 109 (4) 1174 - 1187 0044-4510 1996/04 [Refereed][Not invited]
  • AV Korol, AG Lyalin, AV Solovyov
    PHYSICAL REVIEW A 53 (4) 2230 - 2238 1050-2947 1996/04 [Refereed][Not invited]
     
    The frequency and the angular distributions of photons emitted in the bremsstrahlung process of a 0.2-10 keV electron in collision with Ba are calculated for the photon frequencies above the 4d threshold: omega w=100-200 eV. The polarizational bremsstrahlung is taken into account. A simple method is described for the approximate calculation of the polarizational bremsstrahlung cross section. This method is particularly efficient in the case, when the many-electron correlations are important.
  • A.V. Korol, A.G. Lyalin, A.S. Shulakov, A.V. Solovy'ov
    Journal of Physics B: Atomic, Molecular and Optical Physics 29 (16) L611-L617 - L617 1996 [Refereed][Not invited]
  • AV KOROL, AG LYALIN, AV SOLOVYOV
    JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS 28 (22) 4947 - 4962 0953-4075 1995/11 [Refereed][Not invited]
     
    A new algorithm is introduced for the calculation of the polarizational bremsstrahlung cross section. This method is particularly efficient for carrying out the slowly converging partial-wave series, which characterize the cross section of the process. The frequency and the angular distributions of photons emitted in a collision of a 0.2-10 keV electron with Eu are calculated for the photon frequencies above the 4d-threshold: omega = 100-200 eV. The polarizational bremsstrahlung is taken into account.
  • A.V. Korol, A.G. Lyalin, A.S. Shulakov, A.V. Solov'Yo
    Journal of Physics B: Atomic, Molecular and Optical Physics 28 (6) L155-L160 - L160 1995 [Refereed][Not invited]
  • AG LYALIN, AS SHULAKOV
    FIZIKA TVERDOGO TELA 36 (11) 3185 - 3193 0367-3294 1994/11 [Refereed][Not invited]
  • AS SHULAKOV, AG LYALIN
    OPTIKA I SPEKTROSKOPIYA 74 (3) 447 - 454 0030-4034 1993/03 [Refereed][Not invited]

Books etc

  • Basics of Physics of Polarizational Bremsstrahlung Processes
    Andrey Korol, Andrey Lyalin, Andrey Solov'yov (Single work)
    2010 (ISBN: 9785742224792)
  • Polarizational Bremsstrahlung
    Andrey Korol, Andrey Lyalin, Andrey Solov'yov (Single work)
    2004 (ISBN: 5742205651)


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