Researcher basic information

• 博士（工学）, 東京大学大学院

• https://researchmap.jp/ktakeyasu?lang=en

• https://jglobal.jst.go.jp/detail?JGLOBAL_ID=201601004297516972

• 90739327

• 201601004297516972

• Catalytic reaction
• Vauum science
• Surface chemistry
• Surface physics

• Nanotechnology/Materials, Fundamental physical chemistry

• Master's degree program, Graduate School of Environmental Science
• Doctoral (PhD) degree program, Graduate School of Environmental Science

Research activity information

• Oct. 2025, The Japan Society of Vacuum and Surface Science, Paper award
  Experimental Verification of Mixed-potential-driven Catalysis
  Kotaro Takeyasu;Yuta Katane;Naoto Miyamoto;Mo Yan;Junji Nakamura
• Sep. 2025, NoMaps2025（STARTUP HOKKAIDO), Special Jury Prize and NEDO Award
  Platinum-Free Fuel Cell Catalysts Supporting Disaster Resilience and a Hydrogen Society
  K. Takeyasu;M. Uemura;Y. Ueno;Y. Okazaki;K. Hayashida;K. Homma
• Jan. 2024, つくば研究支援センター, 第4回TCIベンチャーアワード シーズ部門 優秀賞
  低価格・高耐久な白金フリー燃料電池触媒
  武安光太郎
• Oct. 2022, The Physical Society of Japan, The 17th, Young Scientist Award of the Physical Society of Japan
  Studies on flow and controlling factor of energies in surface reactions
  Kotaro Takeyasu
• Jul. 2021, University of Tsukuba, Young Faculty Award
  武安光太郎
• May 2021, 日本表面真空学会, 講演奨励賞（若手研究者部門）
  ミトコンドリア電子伝達系の熱産生解析
  武安光太郎
• Sep. 2018, Catalysis Society of Japan, Grant-in-aid for travel for young scientists
  Kotaro Takeyasu
• 2014, The Vacuum Society of Japan, The 39th Kumagaya Paper Award
  T. Sugimoto;K. Takeyasu;K. Fukutani
• 2014, The Vacuum Society of Japan, The 23rd Vacuum Progress Award
  Kotaro Takeyasu
• Mar. 2013, Institute of Physics, IOP select
  Kotaro Takeyasu
• 2012, The Surface Science Society of Japan, Best Presentation Award for Students
  Kotaro Takeyasu
• 2010, The Japan Society of Applied Physics, Best Presentation Award
  Kotaro Takeyasu
• 2010, The Vacuum Society of Japan, Best Poster Award
  Kotaro Takeyasu

• Nanoarchitectonics of Metal–Organic Framework on Fullerene Assemblies: Fabrication of Hierarchical Nanostructured Carbon Electrocatalysts
  Rabindra Nath Acharyya; Biswa Nath Bhadra; Sabina Shahi; Kenji Hayashida; Shusaku Fujita; Kotaro Takeyasu; Katsuhiko Ariga; Lok Kumar Shrestha
  ACS Applied Materials & Interfaces, 18, 20, 28717, 28727, American Chemical Society (ACS), 15 May 2026, [Peer-reviewed]
  Scientific journal
• Subsurface Graphitic Nitrogen Activates Protonated Pyridinic‐N Sites for Acidic Oxygen Reduction
  Dipti R. Panigrahi; Pranjit Barman; Shouvik Mete; AnilKumar U; Vishal M. Dhavale; Vijay Kumar; Kotaro Takeyasu; Santosh K. Singh
  Small, Wiley, 13 May 2026, [Peer-reviewed], [Corresponding author]
  Scientific journal, ABSTRACT
  
  Protonation of pyridinic nitrogen (pyri‐N) sites in nitrogen‐doped carbon catalysts under acidic conditions converts pyri‐N to pyri‐NH ⁺ , leading to severe catalytic deactivation. Restoring activity requires transforming pyri‐NH ⁺ back to pyri‐NH, an energetically demanding process that limits oxygen reduction reaction (ORR) efficiency. To overcome this challenge, we developed an N‐doped porous carbon catalyst (NpC‐7) featuring surface pyri‐N active sites and a subsurface graphitic nitrogen (grap‐N) layer. The 2D growth of cyanuric acid (CA)‐functionalized 2‐hydroxyethyl methacrylate (HEMA) polymer within graphene oxide layers ensures uniform N‐doping which modulates π‐electron and spin states. This engineered architecture delivers ORR activity approaching Pt/C and surpasses conventional nitrogen doped graphene oxide (NrGO) ( E _onset = 0.86 V, E _1/2 = 0.70 V vs. 0.76 and 0.61 V, respectively). Enhanced performance arises from subsurface grap‐N, which donates electron to protonated pyri‐NH ⁺ , generating an active pyri − NH ^{δ +}  state that promotes O ₂ adsorption. In situ electrochemical Raman spectroscopy and density functional theory (DFT) calculations confirm efficient O ₂ adsorption and intermediate formation, indicating a (2 + 2)e ⁻ ORR pathway. These findings highlight the critical role of subsurface grap‐N in overcoming acidic deactivation through electronic modulation, offering a blueprint for designing acid‐stable carbon electrocatalysts.
• Carbon nanoarchitectonics: design, fabrication and innovation for energy application
  Guoping Chen; Kenji Hayashida; Kaito Homma; Kotaro Takeyasu; Yasuo Yoshida; Taro Koide; Junji Nakamura; Katsuhiko Ariga
  EnergyChem, 8, 3, 100193, 100193, Elsevier BV, May 2026, [Peer-reviewed], [Invited]
  Scientific journal
• Enzymatic oxygen reduction dominates overpotential-driven thermogenesis in mitochondria
  Nuning Anugrah Putri Junji Namari; Mo Yan; Junji Nakamura; Kotaro Takeyasu
  Chemical Science, Royal Society of Chemistry (RSC), Apr. 2026, [Peer-reviewed], [Last author, Corresponding author]
  Scientific journal, Understanding how chemical energy dissipates as heat in non-equilibrium redox systems is a fundamental problem in physical chemistry. While this phenomenon is well described in electrochemical systems such as fuel...
• Emergent Chirality from Pairing of Achiral Molecules: Homochiral Chains of Paired 1,10‐Phenanthroline on Au(111)
  Erlina Tik Man; Yuya Kaneko; Ryunosuke Kobata; Muhammad Alief Irham; Takaya Shimokawa; Tzu‐Yen Chen; Yukiko Obata; Kazutoshi Shimamura; Kenji Hayashida; Kotaro Takeyasu; Taro Koide; Sasfan Arman Wella; Junji Nakamura; Yasuo Yoshida
  Advanced Materials Interfaces, Wiley, 15 Feb. 2026
  Scientific journal, ABSTRACT
  
  Understanding how chirality emerges from assemblies of achiral molecules is central to the study of symmetry breaking at surfaces. Here we show that achiral 1,10‐phenanthroline adsorbed on Au(111) generates chirality through a pairing‐driven hierarchical self‐assembly pathway. Upon adsorption, molecules selectively form hydrogen‐bonded pairs via weak but directional C─H···N interactions. Steric and electrostatic constraints restrict this interaction to two molecules, forcing a choice between two symmetry‐equivalent nitrogen sites and thereby producing left‐ or right‐handed molecular pairs that act as local chiral motifs. These motifs organize through attractive intermolecular interactions into homochiral one‐dimensional chains, which further assemble into two‐dimensional chiral domains governed by repulsive interchain interactions. Scanning tunneling microscopy directly visualizes mirror‐related left‐ and right‐handed domains. Density functional theory calculations confirm that the face‐to‐face paired configuration is energetically preferred and stabilized by adsorption on Au(111). This work reveals a distinct route to surface chirality in which chirality originates at the level of a hydrogen‐bonded molecular pair and is amplified into organized chiral architectures through weak intermolecular interactions.
• Control of Hydration and Degree of p _z /π* Orbital Localization as Dual Keys for Durable Carbon Electrocatalysts in Acidic ORR
  Santosh K. Singh; Kotaro Takeyasu
  ACS Catalysis, American Chemical Society (ACS), 02 Feb. 2026, [Peer-reviewed], [Last author, Corresponding author]
  Scientific journal
• Precise 3D structure determination of Cu single atoms on α-Al ₂ O ₃ (0001) surface by polarization-dependent total reflection fluorescence X-ray absorption fine structure and first-principles calculation
  Bang Lu; Can Liu; Min Gao; Haoran Xu; Daiki Kido; Masao KIMURA; Kotaro Takeyasu; Kiyotaka Asakura; Satoru Takakusagi
  Physical Chemistry Chemical Physics, Royal Society of Chemistry (RSC), 2026, [Peer-reviewed]
  Scientific journal, The valence state and three-dimensional (3D) structure of vacuum-deposited Cu species on an Al-terminated (1×1) α-Al ₂ O ₃ (0001) surface have been studied using polarization-dependent total reflection fluorescence X-ray absorption fine structure (PTRF-XAFS)...
• Controlled Generation of β‐NiOOH by Sulfuric Acid Treatment Enables Active and Durable Oxygen Evolution Catalysis
  Shouvik Mete; Dipti R. Panigrahi; Pranjit Barman; Manish S. Sengar; Marshal Dhayal; Kotaro Takeyasu; Santosh K. Singh
  Chemistry – A European Journal, 32, e03254, Wiley, 23 Dec. 2025, [Peer-reviewed], [Corresponding author]
  Scientific journal, ABSTRACT
  
  Designing oxygen evolution reaction (OER) electrocatalysts that can reversibly operate as both oxidation and reduction electrodes is key to developing efficient and rechargeable electrochemical energy systems. However, the evolution of nickel active sites between hydroxide and oxyhydroxide phases, and how such transformations can be made reversible under dynamic operating conditions, remains poorly understood. Here, we report a sulfuric‐acid‐induced surface oxidation strategy that enables both the controlled formation and reversible regeneration of β‐NiOOH active sites on free‐standing nickel foam electrodes. Moderate H ₂ SO ₄ treatment (1 M) produces an optimized electrode (1.0‐Ni) exhibiting superior OER performance, requiring overpotentials ( η ) of only 218, 348, and 458 mV at 10, 500, and 1000 mA cm ^{− 2} , respectively. The enhanced activity originates from sulfuric‐acid‐induced modulation of Ni sites, which promotes β‐NiOOH formation as the catalytically active phase while maintaining structural integrity. Moreover, a buried β‐NiOOH‐rich layer serves as a structural‐memory reservoir, allowing reversible reconstruction of surface β‐NiOOH during redox cycling. This reversible behavior enables the same electrode to function as both anode and cathode, relevant to rechargeable zinc–air battery and other bifunctional electrochemical systems. The dual mechanism acid‐induced active‐site formation and electrochemical regeneration thus provides a scalable strategy for constructing reversible, heteroatom‐free nickel electrodes for sustainable energy conversion.
• Water‐Enabled CO ₂ Hydrogenation to Ethanol via a Mixed‐Potential‐Driven Mechanism
  Mo Yan; Ryuichi Saito; Nuning A. P. Namari; Paul Bappi; Satoshi Hinokuma; Junji Nakamura; Kotaro Takeyasu
  Chemistry – An Asian Journal, 20, 24, e00862, Wiley, 14 Nov. 2025, [Last author, Corresponding author]
  Scientific journal, ABSTRACT
  
  Ethanol synthesis from CO ₂ and H ₂ is currently a hot topic of research in heterogeneous catalysis. However, the underlying mechanism has not yet been clearly elucidated. We propose that the synthesis involves several other reactions on the electrode surface, as evident by the formation of a mixed potential. In this study, we prepared solid catalysts, Ru/CoO _x and CuPd/C, as the nano‐anode and nano‐cathode components and carried out CO ₂ hydrogenation in the presence of small amounts of water to facilitate ion conduction. Ethanol was produced along with CO, CH ₄ , and methanol at reaction temperatures below 473 K in the presence of both the catalysts. The activation energy for ethanol formation with Ru/CoO _x was found to be 25 ± 5 kJ mol ⁻¹ , which was much lower than those for the formations of CO (44 ± 4 kJ mol ⁻¹ ), CH ₄ (77 ± 7 kJ mol ⁻¹ ), and methanol (81 ± 9 kJ mol ⁻¹ ). In addition, the production of CO was promoted by the encapsulated water. These results also suggest a mixed‐potential‐driven mechanism for the synthesis of ethanol.
• Highly active and stable Fe-N4 catalyst from unused natural resources for oxygen reduction reaction in acidic to alkaline medium
  Edwin Osebe Nyangau; Hiroya Abe; Kazutoshi Haga; Chie Ooka; Kenji Hayashida; Naoka Nagamura; Kotaro Takeyasu; Masaru Watanabe; Yuta Nakayasu
  Journal of Power Sources, 653, 237784, 237784, Elsevier BV, Oct. 2025, [Peer-reviewed]
  Scientific journal
• Deciphering Adsorbate–Adsorbate Interactions from Scanning Tunneling Microscopy Images: Integrated Topological, Statistical, and First-Principles Analysis of Methoxy Adsorbates on Pt/TiO₂(110)
  Can Liu; Min Gao; Daiki Kido; Masao Kimura; Kiyotaka Asakura; Bang Lu; Kotaro Takeyasu; Satoru Takakusagi
  The Journal of Physical Chemistry C, American Chemical Society (ACS), 18 Sep. 2025, [Peer-reviewed]
  English, Scientific journal
• Mixed‐Potential‐Driven Catalysis: An Electrochemical Mechanism for Room‐Temperature CO Oxidation on Gold Catalysts
  Mo Yan; Muhammad Asif; Ravi Singh; Kotaro Takeyasu; Junji Nakamura
  Advanced Science, e05994, Wiley, 25 Jun. 2025, [Peer-reviewed], [Corresponding author]
  English, Scientific journal, Abstract
  
  Gold is an effective catalyst for low‐temperature CO oxidation, yet its mechanism remains debated. Among the various proposed mechanisms, increasing attention has been given to a possible electrochemical pathway in recent studies. Here, experimental evidence is reported that CO oxidation at room temperature in electrolytes proceeds via coupled electrochemical CO oxidation and oxygen reduction half‐reactions, i.e., the mixed‐potential‐driven mechanism. A model system is designed with deposited Au nanoparticles (NPs) and nitrogen‐doped reduced graphene oxide (NrGO) on carbon paper acting as spatially separated electrodes in a single electrolysis cell. After shorting the two electrodes, the reaction current and mixed potential of the overall CO oxidation are measured without any externally applied bias. Independent current–potential curves for each half‐reaction are also obtained under identical experimental conditions. The intersection points of these curves, representing the predicted mixed potential and net current, showed good agreement with the values measured in the short‐circuited system. These results provide clear evidence that CO oxidation in aqueous media proceeds via a mixed‐potential‐driven mechanism, analogous to corrosion. This finding provides strong support for the hypothesis that low‐temperature CO oxidation over‐supported Au catalysts in the presence of water vapor proceeds via a similar electrochemical pathway in gas‐phase heterogeneous catalysis.
• Design Principles of Nitrogen‐Doped Carbon Catalysts for Oxygen Reduction Reaction
  Kenji Hayashida; Bang Lu; Satoru Takakusagi; Junji Nakamura; Kotaro Takeyasu
  ChemElectroChem, 12, 14, Wiley, 20 Jun. 2025, [Peer-reviewed], [Invited], [Last author, Corresponding author]
  Scientific journal, Nitrogen‐doped carbon catalysts are attracting significant attention as alternative electrocatalysts to platinum owing to their high activity and durability in fuel cells’ oxygen reduction reaction (ORR), resource availability, and low catalyst cost. Pyridinic nitrogen forms the active site of the ORR and that the reduction of pyridinium ions is discovered and adsorption of molecular oxygen are coupled with a unique reaction mechanism. The deactivation of nitrogen‐doped carbon catalysts in acid electrolytes is attributed to the protonation of pyridinic nitrogen and the associated hydration is reported. This concept is demonstrated by the increased activity of nitrogen‐doped graphene catalysts, whose hydrophobicity is enhanced by the 3D structure. To further enhance the catalytic activity of nitrogen‐doped carbon catalysts, the electronic configuration of the active sites, particularly the degree of electron localization and spin, plays a crucial role. As an example, the introduction of active sites through five‐membered ring structures is presented, along with their characterization by X‐ray absorption spectroscopy.
• Why Does the Performance of Nitrogen‐Doped Carbon Electrocatalysts Decrease in Acidic Conditions?
  Kenji Hayashida; Junji Nakamura; Kotaro Takeyasu
  Angewandte Chemie International Edition, 64, e202502702, Wiley, 09 May 2025, [Peer-reviewed], [Last author, Corresponding author]
  Scientific journal, Abstract
  
  Nitrogen‐doped carbon has emerged as a promising low‐cost and durable alternative to platinum catalysts for the oxygen reduction reaction (ORR) in fuel cells. However, its catalytic activity decreases significantly in acidic electrolytes, limiting the practical applications. Here, we report the degradation mechanisms of nitrogen‐doped carbon catalysts, focusing on the acid‐base equilibrium of pyridinic nitrogen (pyri‐N), which serves the primary active site. We found that the electrochemical hydrogenation of pyri‐N to pyri‐NH, coupled with oxygen adsorption, is a critical process. Although this reaction occurs at higher potentials in basic electrolytes, it shifts to lower potentials in acidic environments due to the protonation and stabilization of pyri‐N. These results demonstrate that the decrease of the catalytic activity in acidic electrolytes is tied to the basicity of pyri‐N. By controlling the basicity of pyri‐N, specifically its pK_a, a guideline for enhancing the ORR and other electrode reactions has been established.
• Aqueous alkaline pH stable halide ((PEA)₂CoCl₄) perovskite for oxygen reaction electrocatalysis
  Pranjit Barman; Vijay Kumar; Kotaro Takeyasu; Santosh K. Singh
  Journal of Materials Chemistry A, 13, 22, 16437, 16449, Royal Society of Chemistry (RSC), May 2025, [Peer-reviewed]
  Scientific journal, Despite gaining significant importance as an exciting class of materials, the extremely low stability of metal halide perovskites (MHPs) under aqueous medium impedes their potential application beyond photovoltaics and photocatalysis....
• Π-Electron and pH-Regulated Photochemical Detection of Trinitrophenol Using Nanoconfined Graphene Quantum Dots
  Dipti R. Panigrahi; Shashikana Paria; Mridul Jain; Manish S. Sengar; Marshal Dhayal; Bappi Paul; Prasenjit Maity; Kotaro Takeyasu; Vijay Kumar; Santosh K. Singh
  ACS Applied Nano Materials, 8, 5, 2614, 2622, American Chemical Society (ACS), 23 Jan. 2025, [Peer-reviewed]
  Scientific journal
• Pentagon‐Rich Caged Carbon Catalyst for the Oxygen Reduction Reaction in Acidic Electrolytes
  Guoping Chen; Miho Isegawa; Taro Koide; Yasuo Yoshida; Koji Harano; kenji Hayashida; Shusaku Fujita; Kotaro Takeyasu; Katsuhiko Ariga; Junji Nakamura
  Angewandte Chemie International Edition, Wiley, 21 Sep. 2024
  Scientific journal, The interaction between electron spin and oxygen molecules in non‐platinum catalysts, particularly carbon catalysts, significantly influences the catalytic performance of the oxygen reduction reaction (ORR). A promising approach to developing high‐performance catalysts involves introducing five‐membered ring structures with spin electrons into graphitic carbons. In this study, we present the successful synthesis of cage‐like cubic carbon catalysts enriched with pentagon structures using pentagon ring‐containing C60 and a NaCl template. The number of pentagons contained in the structure was increased by doping with nitrogen and annealing, and the number of electron spins also increased, thereby improving catalytic activity. The prepared catalyst exhibits remarkable activity in ORR under acidic electrolytes. Furthermore, we elucidate the correlation between the pentagon structure, the number of spin electrons, and catalytic activity, demonstrating that enhanced activity is contingent upon the presence of spin electrons. Density functional theory (DFT) calculations support the role of spin electrons in improving activity. The concept of spin electrons and the introduction of pentagon structures provide new design principles for carbon catalysts.
• Simultaneous Measurement of Oxygen Consumption Rate and Thermogenesis in Biological Systems for Non-equilibrium Energetics
  Nuning Anugrah Putri Namari; Mo Yan; Junji Nakamura; Kotaro Takeyasu
  e-Journal of Surface Science and Nanotechnology, 22, 3, 273, 278, Surface Science Society Japan, 13 Jul. 2024, [Peer-reviewed], [Last author, Corresponding author]
  Scientific journal
• Mixed-Potential-Driven Catalysis in Glucose Oxidation
  Mo Yan; Rafiq Arsyad; Nuning Anugrah Putri Namari; Hiroaki Suzuki; Kotaro Takeyasu
  ChemCatChem, 16, 17, e202400322, Wiley, 14 Jun. 2024, [Peer-reviewed], [Last author, Corresponding author]
  Scientific journal, Abstract
  
  Mixed‐potential‐driven catalysis, in which anodic and cathodic reactions are electrochemically short‐circuited, converts the Gibbs free energy difference into overpotentials that drive both half‐reactions without an external energy input. We developed a theoretical framework that suggests that the catalytic activities of individual catalyst components determine the distribution of the aforementioned driving forces. By short‐circuiting spatially separated electrodes made of Au/C with reduced‐graphene oxide, nitrogen‐doped reduced‐graphene oxide, caged nitrogen‐doped reduced‐graphene oxide, Pt/C, or Pd/C, we demonstrated this framework using glucose oxidation as a model, given its significance in generating high‐value products and its potential in fuel cell technology. A short‐circuit current was detected in the absence of external potentials, demonstrating electron transfer during glucose oxidation. Additionally, by correlating the mixed potential predicted from the polarization curves of each half‐reaction with the mixed potential measured in short‐circuit experiments under the same conditions, we confirmed that the kinetic activity of each catalyst component determines the mixed potential. This, in turn, affects the division of the driving force. Driving force partitioning is a potent tool for enhancing the overall rate of a reaction. Our findings may facilitate the design of not only glucose oxidation catalysts but also other heterogeneous catalysts based on mixed‐potential‐driven reaction mechanisms.
• Theoretical framework for mixed-potential-driven catalysis
  Mo Yan; Nuning Anugrah Putri Namari; Junji Nakamura; Kotaro Takeyasu
  Communications Chemistry, 7, 1, Springer Science and Business Media LLC, 01 Apr. 2024, [Peer-reviewed], [Last author, Corresponding author]
  Scientific journal, Abstract
  
  Mixed-potential-driven catalysis is expected to be a distinctive heterogeneous catalytic reaction that produces products different from those produced by thermal catalytic reactions without the application of external energy. Electrochemically, the mechanism is similar to that of corrosion. However, a theory that incorporates catalytic activity as a parameter has not been established. Herein, we report the theoretical framework of mixed-potential-driven catalysis, including exchange currents, as a parameter of catalytic activity. The mixed potential and partitioning of the overpotential were determined from the exchange current by applying the Butler–Volmer equation at a steady state far from equilibrium. Mixed-potential-driven catalysis is expected to open new areas not only in the concept of catalyst development but also in the field of energetics of biological enzymatic reactions.
• Facile fabrication of graphitic carbon nitride/polydopamine/polyurethane foam as a floating photocatalyst for synthetic dye remediation
  Indra J. Budiarso; Shusaku Fujita; Shota Saito; Hermawan Judawisastra; Kotaro Takeyasu; Arie Wibowo
  Reaction Chemistry & Engineering, 9, 10, 2718, 2727, Royal Society of Chemistry (RSC), 2024, [Peer-reviewed]
  Scientific journal, Carbon nitride-based floating photocatalyst supported on polyurethane foam using polydopamine: evaluation of fabrication processes, properties, performance, and mechanism.
• Catalytic function of nitrogen-doped carbon
  Kenji Hayashida; Junji Nakamura; Kotaro Takeyasu
  Accounts of Materials & surface Research, 8, 135, 146, Oct. 2023, [Peer-reviewed], [Invited], [Last author, Corresponding author]
• Rhombohedral Boron Monosulfide as a p-Type Semiconductor
  Norinobu Watanabe; Keisuke Miyazaki; Masayuki Toyoda; Kotaro Takeyasu; Naohito Tsujii; Haruki Kusaka; Akiyasu Yamamoto; Susumu Saito; Masashi Miyakawa; Takashi Taniguchi; Takashi Aizawa; Takao Mori; Masahiro Miyauchi; Takahiro Kondo
  Molecules, 28, 4, 1896, 1896, MDPI AG, 16 Feb. 2023, [Peer-reviewed]
  Scientific journal, Two-dimensional materials have wide ranging applications in electronic devices and catalysts owing to their unique properties. Boron-based compounds, which exhibit a polymorphic nature, are an attractive choice for developing boron-based two-dimensional materials. Among them, rhombohedral boron monosulfide (r-BS) has recently attracted considerable attention owing to its unique layered structure similar to that of transition metal dichalcogenides and a layer-dependent bandgap. However, experimental evidence that clarifies the charge carrier type in the r-BS semiconductor is lacking. In this study, we synthesized r-BS and evaluated its performance as a semiconductor by measuring the Seebeck coefficient and photo-electrochemical responses. The properties unique to p-type semiconductors were observed in both measurements, indicating that the synthesized r-BS is a p-type semiconductor. Moreover, a distinct Fano resonance was observed in Fourier transform infrared absorption spectroscopy, which was ascribed to the Fano resonance between the E(2) (TO) phonon mode and electrons in the band structures of r-BS, indicating that the p-type carrier was intrinsically doped in the synthesized r-BS. These results demonstrate the potential future application prospects of r-BS.
• Critical impacts of interfacial water on C–H activation in photocatalytic methane conversion
  Hiromasa Sato; Atsushi Ishikawa; Hikaru Saito; Taisuke Higashi; Kotaro Takeyasu; Toshiki Sugimoto
  Communications Chemistry, 6, 1, Springer Science and Business Media LLC, 20 Jan. 2023
  Scientific journal, Abstract
  
  On-site and on-demand photocatalytic methane conversion under ambient conditions is one of the urgent global challenges for the sustainable use of ubiquitous methane resources. However, the lack of microscopic knowledge on its reaction mechanism prevents the development of engineering strategies for methane photocatalysis. Combining real-time mass spectrometry and operando infrared absorption spectroscopy with ab initio molecular dynamics simulations, here we report key molecular-level insights into photocatalytic green utilization of methane. Activation of the robust C–H bond of methane is hardly induced by the direct interaction with photogenerated holes trapped at the surface of photocatalyst; instead, the C–H activation is significantly promoted by the photoactivated interfacial water species. The interfacial water hydrates and properly stabilizes hydrocarbon radical intermediates, thereby suppressing their overstabilization. Owing to these water-assisted effects, the photocatalytic conversion rates of methane under wet conditions are dramatically improved by typically more than 30 times at ambient temperatures (~300 K) and pressures (~1 atm) in comparison to those under dry conditions. This study sheds new light on the role of interfacial water and provides a firm basis for design strategies for non-thermal heterogeneous catalysis of methane under ambient conditions.
• Electronic Structure and Reaction Mechanism on Nitrogen-doped Carbon Electrode Catalysts and Design of Catalyst Based on the Mechanism
  Kotaro TAKEYASU; Junji NAKAMURA
  Vacuum and Surface Science, 66, 1, 10, 15, Surface Science Society Japan, 10 Jan. 2023, [Peer-reviewed], [Invited], [Lead author, Corresponding author]
  Scientific journal
• Experimental Verification of Mixed-potential-driven Catalysis
  Kotaro Takeyasu; Yuta Katane; Naoto Miyamoto; Mo Yan; Junji Nakamura
  e-Journal of Surface Science and Nanotechnology, 21, 3, 164, 168, Surface Science Society Japan, 28 Dec. 2022, [Peer-reviewed], [Lead author, Corresponding author]
  Scientific journal
• Chemisorption of CO₂ on Nitrogen-Doped Graphitic Carbons
  Riku Shibuya; Kotaro Takeyasu; Donghui Guo; Takahiro Kondo; Junji Nakamura
  Langmuir, 38, 47, 14430, 14438, American Chemical Society (ACS), 15 Nov. 2022
  Scientific journal
• Activating Nitrogen‐doped Graphene Oxygen Reduction Electrocatalysts in Acidic Electrolytes using Hydrophobic Cavities and Proton‐conductive Particles
  Santosh K. Singh; Kotaro Takeyasu; Kaito Homma; Shigeharu Ito; Takashi Morinaga; Yuto Endo; Moeko Furukawa; Toshiyuki Mori; Hirohito Ogasawara; Junji Nakamura
  Angewandte Chemie International Edition, Wiley, 14 Oct. 2022, [Peer-reviewed], [Lead author, Corresponding author]
  Scientific journal
• Hollow Spherical Fullerene obtained by Kinetically Controlled Liquid‐Liquid Interfacial Precipitation
  Guoping Chen; Flavien Sciortino; Kotaro Takeyasu; Junji Nakamura; Jonathan Patrick Hill; Lok Kumar Shrestha; Katsuhiko Ariga
  Chemistry – An Asian Journal, e202200756, Wiley, 23 Aug. 2022, [Peer-reviewed]
  Scientific journal
• Hydrogenation of Formate Species Using Atomic Hydrogen on a Cu(111) Model Catalyst
  Kotaro Takeyasu; Yasutaka Sawaki; Takumi Imabayashi; Septia Eka Marsha Putra; Harry Handoko Halim; Jiamei Quan; Yuji Hamamoto; Ikutaro Hamada; Yoshitada Morikawa; Takahiro Kondo; Tadahiro Fujitani; Junji Nakamura
  Journal of the American Chemical Society, 144, 27, 12158, 12166, 13 Jul. 2022, [Peer-reviewed], [Lead author]
  English, Scientific journal
• Versatile nanoarchitectonics of Pt with morphology control of oxygen reduction reaction catalysts
  Guoping Chen; Santosh K. Singh; Kotaro Takeyasu; Jonathan P. Hill; Junji Nakamura; Katsuhiko Ariga
  Science and Technology of Advanced Materials, 23, 1, 413, 423, Informa UK Limited, 22 Jun. 2022, [Peer-reviewed]
  Scientific journal
• Focusing and spin polarization of atomic hydrogen beam
  Y. Nagaya; H. Nakatsu; S. Ogura; K. Shimazaki; H. Ueta; K. Takeyasu; K. Fukutani
  The Journal of Chemical Physics, 155, 19, 194201, AIP Publishing, 21 Nov. 2021, [Peer-reviewed]
  Scientific journal
• Role of Pyridinic Nitrogen in the Mechanism of the Oxygen Reduction Reaction on Carbon Electrocatalysts
  Kotaro Takeyasu; Moeko Furukawa; Yuto Shimoyama; Santosh K. Singh; Junji Nakamura
  Angewandte Chemie International Edition, 60, 10, 5121, 5124, Mar. 2021, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• CoOx electro-catalysts anchored on nitrogen-doped carbon nanotubes for the oxygen evolution reaction
  Santosh K. Singh; Kotaro Takeyasu; Bappi Paul; Sachin K. Sharma; Junji Nakamura
  Sustainable Energy & Fuels, 5, 3, 820, 827, Royal Society of Chemistry (RSC), Jan. 2021, [Peer-reviewed]
  Scientific journal,

  The development of high-performance, low-cost transition metal oxide nanoparticle-supported carbon catalysts for oxygen evolution reaction (OER) is one of the biggest challenges faced in the process of commercializing water electrolyzers and rechargeable metal–air batteries.

• Dynamical Quantum Filtering via Enhanced Scattering of para-H2 on the Orientationally Anisotropic Potential of SrTiO3(001)
  Koji Shimizu; Wilson Agerico Diño; Hiroshi Nakanishi; Hideaki Kasai; Kotaro Takeyasu; Katsuyuki Fukutani; Ayako Yajima
  Scientific Reports, 10, 1, 5939, Springer Science and Business Media LLC, Dec. 2020
  Scientific journal, Quantum dynamics calculation, performed on top of density functional theory (DFT)-based total energy calculations, show dynamical quantum filtering via enhanced scattering of para-H₂ on SrTiO₃(001). We attribute this to the strongly orientation-dependent (electrostatic) interaction potential between the H₂ (induced) quadrupole moment and the surface electric field gradient of ionic SrTiO₃(001). These results suggest that ionic surfaces could function as a scattering/filtering media to realize rotationally state-resolved H₂. This could find significant applications not only in H₂ storage and transport, but also in realizing materials with pre-determined characteristic properties.
• Local electronic structure and activity of nitrogen-doped carbon
  Kotaro Takeyasu; Junji Nakamura
  TANSO, 2019, 290, 204, 210, The Carbon Society of Japan, 15 Nov. 2019, [Peer-reviewed], [Invited], [Lead author]
  Scientific journal
• Active Sites and Mechanism of Oxygen Reduction Reaction Electrocatalysis on Nitrogen-Doped Carbon Materials
  Santosh K. Singh; Kotaro Takeyasu; Junji Nakamura
  Advanced Materials, 31, 13, 1804297, 1804297, Wiley, Mar. 2019, [Peer-reviewed], [Invited]
  Scientific journal
• Electronic and spin structure of O- and H-adsorbed Fe3O4(111) surfaces
  Asakawa, Kanta; Miura, Yoshio; Nagatsuka, Naoki; Takeyasu, Kotaro; Matsumoto, Masuaki; Fukutani, Katsuyuki
  PHYSICAL REVIEW B, 99, 8, 085442, Feb. 2019, [Peer-reviewed]
  English, Scientific journal
• Argument on Cu-Zn Active Site for Methanol Synthesis
  Kotaro Takeyasu; Tadahiro Fujitani; Junji Nakamura
  Accounts of Materials & Surface Research, 4, 9, 17, Jan. 2019, [Peer-reviewed], [Invited]
  Japanese, Scientific journal
• Adsorption geometry of methyl chloride weakly interacting with Ag(111)
  K. Takeyasu; M. Okada
  J. Phys. Commun., 2, 075017, May 2018, [Peer-reviewed]
  English, Scientific journal
• Effects of Hydrogen on the Electronic State and Electric Conductivity of the Rutile TiO2(110) Surface
  Keisuke Fukada; Masuaki Matsumoto; Kotaro Takeyasu; Shohei Ogura; Katsuyuki Fukutani
  JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 84, 6, 064716, Jun. 2015, [Peer-reviewed]
  English, Scientific journal
• Temperature dependence of hydrogen depth distribution in the near-surface region of stainless steel
  Kotaro Takeyasu; Masuaki Matsumoto; Katsuyuki Fukutani
  VACUUM, 109, 230, 233, Nov. 2014, [Peer-reviewed]
  English, Scientific journal
• Electronic structure of the SrTiO3 (001) surfaces: Effects of the oxygen vacancy and hydrogen adsorption
  K. Takeyasu; K. Fukada; S. Ogura; M. Matsumoto; K. Fukutani
  Appl. Sci. Conv. Technol., 23, 5, 201, 210, Sep. 2014, [Peer-reviewed], [Invited]
  English, Scientific journal
• Two charged states of hydrogen on the SrTiO3(001) surface
  Kotaro Takeyasu; Keisuke Fukada; Shohei Ogura; Masuaki Matsumoto; Katsuyuki Fukutani
  JOURNAL OF CHEMICAL PHYSICS, 140, 8, 084703, Feb. 2014, [Peer-reviewed]
  English, Scientific journal
• Hydrogen-Induced Dipoles and Sensing Principles of Pt-Ti-O gate Si-MISFET Hydrogen Gas Sensors
  Toshiyuki Usagawa; Kotaro Takeyasu; Katsuyuki Fukutani
  28TH EUROPEAN CONFERENCE ON SOLID-STATE TRANSDUCERS (EUROSENSORS 2014), 87, 1015, 1018, 2014, [Peer-reviewed]
  English, International conference proceedings
• Analytical Formula for Calculating Adsorption Density of States on Chamber Surfaces from Measured Pressure Change
  Takeyasu, Kotaro; Sugimoto, Toshiki; Fukutani, Katsuyuki
  JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 82, 11, 114602, Nov. 2013, [Peer-reviewed]
  English, Scientific journal
• Control of the surface electronic structure of SrTiO3(001) by modulation of the density of oxygen vacancies
  Kotaro Takeyasu; Keisuke Fukada; Masuaki Matsumoto; Katsuyuki Fukutani
  JOURNAL OF PHYSICS-CONDENSED MATTER, 25, 16, 162202, Apr. 2013, [Peer-reviewed]
  English, Scientific journal
• Gas dynamics in the vacuum chamber with a single adsorption site on the wall surface: Origin of the exponential pressure decay with the time constant of sub-kilo seconds
  Toshiki Sugimoto; Kotaro Takeyasu; Katsuyuki Fukutani
  Journal of the Vacuum Society of Japan, 56, 8, 322, 329, 2013, [Peer-reviewed]
  Japanese, Scientific journal
• Analysis of a pumping curve of water with the conversion equation from pressure to adsorption density of states
  Kotaro Takeyasu; Toshiki Sugimoto; Katsuyuki Fukutani
  Journal of the Vacuum Society of Japan, 56, 11, 457, 460, 2013, [Peer-reviewed], [Invited]
  Japanese, Scientific journal
• Theoretical analysis of a spin-polarized atomic hydrogen beam optics
  Shohei Ogura; Kotaro Takeyasu; Katsuyuki Fukutani
  Journal of the Vacuum Society of Japan, 54, 3, 192, 195, 2011, [Peer-reviewed]
  Japanese, International conference proceedings
• Structural study of clean and gas adsorbed metal surfaces by low-energy electron diffraction
  K. Takeyasu; K. Fukada; S. Ogura; M. Matsumoto; K. Fukutani
  SEISAN KENKYU, 61, 5, 945, 948, Institute of Industrial Science The University of Tokyo, Feb. 2010
  Japanese, 本研究では, 低速電子線回折法(LEED)を用いてイリジウム(Ir)(111)清浄表面及び一酸化窒素(NO)吸着表面の二つの試料について, スポット強度の温度依存性の解析と動力学的解析によってデバイ温度を評価した．LEEDスポット強度の温度依存性を用いた解析ではIr (111)清浄表面におけるデバイ温度は250～280K, NO吸着表面におけるデバイ温度は220～235K程度であることが分かった．また動力学的解析結果からはIr (111)清浄表面におけるデバイ温度は310K, バルクのデバイ温度が440 Kとなり, 表面ではバルクよりも低い値となることが分かった．表面でのデバイ温度が低いことは表面原子の振動振幅がバルク内部に比べて大きいことを示しており, さらに表面にNOが吸着することによりさらに増大すると考えられる．［本要旨はPDFには含まれない］

• ミトコンドリアダイナミクス～機能研究から疾患・老化まで～
  武安光太郎; Nuning Anugrah; Putri Namari; 中村潤児, ミトコンドリア電子伝達系と熱産生メカニズム
  2021, [Contributor]
• 触媒技術の動向と展望2020
  武安光太郎; 中村潤児, 表面科学的手法による触媒研究の動向と課題
  2020, [Contributor]

• ミトコンドリア呼吸鎖における過電圧散逸としての生体熱生成機構
  武安光太郎
  第63回日本伝熱シンポジウム, 27 May 2026
  26 May 2026 - 28 May 2026, [Invited]
• Hybrid thermochemical–electrochemical catalysis enabled by mixed potentials: design of green CO₂ conversion reactions
  Kotaro Takeyasu
  Modern Aspects of Green and Sustainable Chemistry 2026, 29 Jan. 2026
  27 Jan. 2026 - 31 Jan. 2026, [Invited]
• Carbon catalysts: from fuel cell half-reactions to low-temperature heterogeneous catalysis
  Kotaro Takeyasu
  Singapore Scientific Conference 2025, 08 Dec. 2025
  06 Dec. 2025 - 10 Dec. 2025, [Invited]
• Carbon catalysts: from fuel cell half-reactions to low-temperature heterogeneous catalysis
  Kotaro Takeyasu
  NUS-ICAT Joint International Symposium, 28 Oct. 2025, English, Invited oral presentation
  28 Oct. 2025 - 29 Oct. 2025, [Invited]
• Experimental Verification of Mixed-potential-driven Catalysis
  Experimental Verification of Mixed-potential-driven Catalysis
  Annual Meeting of the Japan Society of Vacuum and Surface Science 2025, 20 Oct. 2025, Invited oral presentation
  20 Oct. 2025 - 22 Oct. 2025, [Invited]
• Protonation and hydration effects in carbon catalysts and catalytic design by mixed potential
  Kotaro Takeyasu
  第６回ハイドロジェノミクス研究会, 16 Oct. 2025
  16 Oct. 2025 - 16 Oct. 2025, [Invited]
• 不均一系・電極触媒反応のメカニズム解明と融合
  武安光太郎
  学際統合物質科学研究機構 若手共創ワークショップ, 02 Oct. 2025
  02 Oct. 2025 - 03 Oct. 2025
• 電子状態と混成電位の制御に基づく カーボン触媒反応の俯瞰と設計論
  武安 光太郎
  第136回触媒討論会, 17 Sep. 2025, Japanese, Invited oral presentation
  17 Sep. 2025 - 19 Sep. 2025, [Invited]
• Design Strategy of Carbon Catalysts for Oxygen Reduction and Mixed-Potential-Driven Catalysis
  Kotaro Takeyasu
  3rd International Conference on Catalysis Science and Chemical Engineering, 21 Jul. 2025, English, Invited oral presentation
  20 Jul. 2025 - 22 Jul. 2025, [Invited]
• Mixed-potential-driven catalysis: From glucose oxidation to CO oxidation
  Kotaro Takeyasu
  Hanyang University and ICAT Joint Research Symposium, 16 Jul. 2025, English, Invited oral presentation
  16 Jul. 2025 - 16 Jul. 2025, [Invited]
• 表面科学で見る電気化学：カーボン系触媒の限界拡張へ
  武安光太郎
  日本表面真空学会 第8回若手部会研究会 & 関東支部10周年記念シンポジウム, 17 Apr. 2025
  [Invited]
• Designing Carbon Catalysts for Oxygen Reduction and Mixed-Potential-Driven Catalysis
  Kotaro Takeyasu
  The 2 nd International Conference on Advanced Functional Materials (ICAFM 2025), 27 Mar. 2025
  27 Mar. 2025 - 29 Mar. 2025, [Invited]
• 表面科学を基盤とした電気化学反応触媒の理解と設計
  武安光太郎
  日本表面真空学会東北・北海道支部学術講演会, 10 Mar. 2025
  [Invited]
• 表面科学によるカーボン系電極触媒の限界突破
  武安光太郎
  大分大学DX研究会, 05 Feb. 2025
  [Invited]
• Thermochemical and electrochemical mixed reaction systems based on carbon-based catalysts
  Kotaro Takeyasu
  Shiv Nadar University Department of Chemistry Seminar, 17 Jan. 2025, English, Invited oral presentation
  17 Jan. 2025 - 17 Jan. 2025, [Invited]
• 電子状態設計に基づくカーボン電極触媒の限界突破に向けて
  武安光太郎
  第2回北海道大学触媒科学研究所-立命館大学 SRセンター合同シンポジウム, 25 Dec. 2024
  25 Dec. 2024 - 25 Dec. 2024, [Invited]
• Mechanism-driven design of metal-free nitrogen-doped carbon electrocatalyst for oxygen reduction reaction
  Kotaro Takeyasu
  12th Singapore International Conference on Chemistry (SICC-12), 12 Dec. 2024
  09 Dec. 2024 - 13 Dec. 2024, [Invited]
• 混成電位駆動型触媒反応の理論的枠組みと実験的検証
  武安光太郎
  第134回触媒討論会, 13 Sep. 2024, Invited oral presentation
  [Invited]
• 窒素ドープカーボン触媒の活性低下メカニズムに基づく高性能化
  武安光太郎
  第31回燃料電池シンポジウム, 24 May 2024, Invited oral presentation
  24 May 2024 - 24 May 2024, [Invited]
• Mechanism-based design of metal-free nitrogen-doped carbonelectrocatalyst for oxygen reduction reaction
  Kotaro Takeyasu
  9th Asian Conference on Colloid and Interface Science 2023, 13 Dec. 2023
  12 Dec. 2023 - 15 Dec. 2023, [Invited]
• Electrochemical relationship of thermogenesis, oxygen consumption, and ROS production in mitochondrial respiratory chain
  Kotaro Takeyasu; Nuning Namari; Junji Nakamura
  The 96th Annual Meeting of the Japanese Biochemical Society, 02 Nov. 2023, Invited oral presentation
  31 Oct. 2023 - 02 Nov. 2023, [Invited]
• Elucidation of reaction mechanism on carbon catalysts and its application to catalyst design and understanding of biological reactions
  Kotaro Takeyasu
  China-Japan International Symposium on Photonic Materials, 31 Jul. 2023
  30 Jul. 2023 - 31 Jul. 2023, [Invited]
• 酸化グラフェンを基盤とした窒素ドープグラフェン酸素還元反応触媒の疎水性籠状構造とプロトン伝導粒子による高性能化
  武安光太郎
  第19回酸化グラフェンナノシートシンポジウム, 23 Jun. 2023
  23 Jun. 2023 - 23 Jun. 2023, [Invited]
• ミトコンドリア呼吸鎖における反応駆動由来の熱産生解析
  武安光太郎; Nuning Anugrah; Putri Namari; 中村潤児
  第21回ミトコンドリア学会 年会, 08 Mar. 2023, Invited oral presentation
  08 Mar. 2023 - 08 Mar. 2023, [Invited]
• Mechanism of thermogenesis in mitochondrial respiratory chain
  K. Takeyasu
  The Biophysical Society of Japan Annual Meeting, symposium, 18 Sep. 2022, English, Invited oral presentation
  [Invited], [International presentation]
• Detection of unstable intermediates for CO2 conversion into methanol on a Cu(111) model catalyst
  K. Takeyasu
  6th International Conference on Catalysis and Chemical Engineering, 22 Feb. 2022, English, Invited oral presentation
  [Invited], [International presentation]
• Role of pyridinic nitrogen as an active site of carbon catalysts
  K. Takeyasu
  Physical Society of Japan Meeting, symposium, 18 Sep. 2021, English, Invited oral presentation
  [Invited], [International presentation]
• Oxygen adsorption state on a nitrogen-doped graphene model catalyst
  K. Takeyasu
  The 128th Catalysis Society of Japan, Symposium by Young Scientists, 16 Sep. 2021, Japanese, Invited oral presentation
  [Invited], [International presentation]
• Recent improvement of N-doped graphene catalysts for oxygen reduction reaction by hydrophobization
  K. Takeyasu
  12th New Electrode Symposium and Seminar, 01 Nov. 2019, Japanese, Invited oral presentation
  [Invited], [International presentation]
• ORR active site of nitrogen-doped carbon materials
  K. Takeyasu
  Post Kei Topic 5 Workshop by young researchers, 29 Aug. 2019, Japanese, Invited oral presentation
  [Invited], [International presentation]
• Effective local structure and reaction mechanisms for bottom-up designed metal-free ORR catalyst
  K. Takeyasu
  International Congress on Pure and Applied Chemistry, 06 Aug. 2019, English, Invited oral presentation
  [Invited], [International presentation]
• Oxygen reduction reaction on aromatic-molecule-base catalysts activated by adsorbed hydrogen
  K. Takeyasu; Y. Shimoyama; M. Furukawa; S. K. Singh; J. Nakamura
  1st Hydrogenomics Workshop, 16 Nov. 2018, Japanese, Oral presentation
  [Domestic Conference]
• Effective local structure for pyridinic nitrogen in carbon-based ORR catalyst synthesized with a bottom-up approach
  K. Takeyasu; Y. Shimoyama; M. Furukawa; S. K. Singh; J. Nakamura
  Southeast Asia Collaborative Symposium on Energy Materials 2018, 08 Nov. 2018, English, Invited oral presentation
  [Invited], [International presentation]
• Effective Local Structure for Bottom-up Designed ORR Catalyst Using Pyridinic Nitrogen Containing Molecules
  K. Takeyasu; Y. Shimoyama; M. Furukawa; S. K. Singh; J. Nakamura
  American Vacuum Society 60th Symposium, 23 Oct. 2018, English, Oral presentation
  [International presentation]
• Activation mechanisms for ORR catalysts with pyridinicnitrogen containing molecules
  K. Takeyasu; Y. Shimoyama; M. Furukawa; S. K. Singh; J. Nakamura
  122nd Meeting of Catalysis Society of Japan, 27 Sep. 2018, Oral presentation
  [Domestic Conference]
• Anisotropy of angular distribution of molecular hydrogen scattered on a oxide surface -Filtering of nuclear spin-
  Kotaro Takeyasu
  Workshop on Photon Science for Young Researchers, 09 Apr. 2016, Japanese, Invited oral presentation
  [Invited], [Domestic Conference]
• Steric effects of molecules in surface scattering and reaction processes
  Kotaro Takeyasu
  The 9th Kishu Yoshimune seminner, 12 Feb. 2016, Japanese, Invited oral presentation
  [Invited], [Domestic Conference]
• Molcular desorption and pressure change on a vacuum chamber surface -Derivation of adsorption density of states
  Kotaro Takeyasu
  The Vacuum Society of Japan Regular Workshop, 13 Jul. 2012, Japanese, Invited oral presentation
  [Invited], [Domestic Conference]
• Derivation of adsorption density of states on vacuum chamber surfaces by pressure decay curves
  Kotaro Takeyasu
  KEK Accelerator Seminner, 20 Dec. 2011, Japanese, Invited oral presentation
  [Invited], [Domestic Conference]

• Development of Design Guidelines for Catalyst Functionality via Visualization of Reaction Field Fluctuation Structures
  JST Strategic BAsic Research Program (PRESTO)
  Oct. 2025 - Mar. 2029
  Japan Science and Technology Agency, Principal investigator, 25146494
• Functional elucidation of nitrogen-doped carbon catalysts and their application to energy materials
  Grants-in-Aid for Scientific Research
  12 Apr. 2023 - 31 Mar. 2028
  中村 潤児; 吉田 靖雄; 有賀 克彦; 武安 光太郎
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (S), Kyushu University, 23H05459
• Low-temperature Selective Conversion of $CO_2$ via Mixed Potential-Driven Reaction Fields
  Project to Support Research and Development of Carbon Recycling-related Technologies
  Oct. 2025 - Sep. 2027
  Hiroshima prefecture, Principal investigator
• 窒素ドープカーボン触媒の機能解明とエネルギー材料への応用
  科学研究費助成事業
  01 Apr. 2023 - 31 Mar. 2026
  中村 潤児; 吉田 靖雄; 有賀 克彦; 武安 光太郎
  日本学術振興会, 基盤研究(A), 九州大学, 23H00246
• Electron orbital effects on the catalytic performance of nitrogen-doped graphene
  Grants-in-Aid for Scientific Research
  2024 - 2026
  武安 光太郎
  Japan Society for the Promotion of Science, Fund for the Promotion of Joint International Research (Fostering Joint International Research), 23KK0266
• Scale Effect of π-Electron System on Oxygen Reduction Reaction Activity of Nitrogen-Doped Graphene
  Grants-in-Aid for Scientific Research (Young researchers)
  Apr. 2022 - Mar. 2025
  Kotaro Takeyasu
  Japan Society for the Promotion of Science, Principal investigator, Competitive research funding
• Development of a flow-type mixed potential-driven CO2 reduction reaction system
  Tsukuba Industry-Academia Collaboration Enhancement Project
  01 Apr. 2022 - 31 Mar. 2023
  Kotaro Takeyasu
  Japan Society for the Promotion of Science, Principal investigator, Competitive research funding
• Material design and mechanistic study of carbon electro-catalysts for fuel cells
  Grants-in-Aid for Scientific Research
  01 Apr. 2020 - 31 Mar. 2023
  中村 潤児; 有賀 克彦; 岡田 晋; 近藤 寛; 神原 貴樹; 武安 光太郎
  窒素ドープカーボン触媒は白金を使用しない燃料電池カソード触媒として最も期待されている。我々は、2016年にピリジン型窒素が活性点を形成することを世界に先駆けて報告した（Science誌、2016年）。本研究では、ピリジン型窒素の役割を明らかにし、高活性な触媒を開発することを目的としている。2020年度の研究では、ピリジン型窒素含有芳香族系分子をカーボンブラックに担持したモデル触媒を用いてピリジン型窒素の役割の概要が明らかになり、高性能触媒の設計の指針が得られた。すなわち、プロトンがピリジン型窒素に付加して生じるピリジニウムイオンの電気化学的還元と酸素分子のカーボン触媒への熱反応的な吸着がエネルギー的に連動することを明らかになった。この酸素吸着が低活性触媒の場合に反応律速となる。そのためその反応の酸化還元電位がピリジニウムの水和によって著しく低下する。活性劣化を防ぐためににカーボン触媒を疎水性化した結果、高活性触媒な触媒が得られた。以上の研究成果は世界をリードするものと言える。
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), University of Tsukuba, 20H00316
• Non-faradic reaction system to accelerate CO2-alcohol conversion reactions
  Tsukuba Industry-Academia Collaboration Enhancement Project
  01 Apr. 2021 - 31 Mar. 2022
  Kotaro Takeyasu
  Japan Society for the Promotion of Science, Principal investigator, Competitive research funding
• Development of highly active platinum-free fuel cell catalysts based on reaction mechanism
  Kato Foundation for Promotion of Science Research Grant
  01 Apr. 2021 - 31 Mar. 2022
  Kotaro Takeyasu
  Kato Foundation for Promotion of Science, Principal investigator, Competitive research funding
• CO2-alcohol low-temperature conversion by bipolar local electrochemical reaction
  Tsukuba Industry-Academia Collaboration Enhancement Project
  01 Apr. 2020 - 31 Mar. 2021
  Kotaro Takeyasu
  Japan Society for the Promotion of Science, Principal investigator, Competitive research funding
• Four-electron oxygen reduction reaction carbon frame catalyst
  Grants-in-Aid for Scientific Research (Young researchers)
  01 Apr. 2019 - 31 Mar. 2021
  Kotaro Takeyasu
  Japan Society for the Promotion of Science, Principal investigator, Competitive research funding
• Novel alcohol synthesis system due to spontaneous electrochemical reaction
  Tsukuba Basic Research Support Program Type S
  01 Apr. 2018 - 31 Mar. 2019
  Kotaro Takeyasu
  University of Tsukuba, Principal investigator, Competitive research funding
• Development of spin-polarized hydrogen atom scattering system and elucidation of surface magnetic structure
  Grants-in-Aid for Scientific Research (Reserch Fellowship for Young Scientists)
  01 Apr. 2011 - 31 Mar. 2014
  Kotaro Takeyasu
  Japan Society for the Promotion of Science, Principal investigator, Competitive research funding