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2016
1 Citations

Temperature dependence of oxygen reduction mechanism on a titanium oxide-based catalyst made from oxy-titanium tetra-pyrazino-porphyrazine using carbon nano-tubes as support in acidic solution

Hayashi, T., Ishihara, A., Nagai, T., Arao, M., Imai, H., Kohno, Y., Matsuzawa, K., Mitsushima, S. & Ota, K. I. 2016 Aug 10 In : Electrochimica Acta. 209, p. 1-6 6 p.

Research output: Contribution to journalArticle

Oxygen
Titanium oxides
Electrons
Cathodes
Titanium
4 Citations

Titanium-niobium oxides mixed with Ti4O7 as precious-metal-and carbon-free cathodes for polymer electrolyte fuel cells

Ishihara, A., Hamazaki, M., Arao, M., Matsumoto, M., Imai, H., Kohno, Y., Matsuzawa, K., Mitsushima, S. & Ota, K. 2016 In : Journal of the Electrochemical Society. 163, 7, p. F603-F609

Research output: Contribution to journalArticle

Cathodes
Oxides
Oxygen
Precious metals
Fuel cells
2015

Development of group 4 and 5 metal oxide cathode with electron conductive oxide

Ota, K. I., Hamazaki, M., Matsuzawa, K., Mitsushima, S. & Ishihara, A. 2015 ECS Transactions. 17 ed. Electrochemical Society Inc., Vol. 69, p. 13-21 9 p.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Oxides
Oxidation
Electrons
Metals
Metal complexes

Durability of titanium-niobium oxides mixed with ti4o7 as non-preciousand carbon-free cathodes for PEFCs in H2SO4 at 80°C

Hamazaki, M., Ishihara, A., Kohno, Y., Matsuzawa, K., Mitsushima, S. & Ota, K. I. 2015 In : Electrochemistry. 83, 10, p. 817-819 3 p.

Research output: Contribution to journalArticle

Durability
Cathodes
Niobium oxide
Titanium
Carbon
7 Citations

Effect of reheating treatment on oxygen-reduction activity and stability of zirconium oxide-based electrocatalysts prepared from oxy-zirconium phthalocyanine for polymer electrolyte fuel cells

Okada, Y., Ishihara, A., Matsumoto, M., Arao, M., Imai, H., Kohno, Y., Matsuzawa, K., Mitsushima, S. & Ota, K. 2015 Jun 11 In : Journal of the Electrochemical Society. 162, 9, p. F959-F964

Research output: Contribution to journalArticle

Oxygen
Temperature
Graphitization
Electrocatalysts
Zirconium
1 Citations

Kinetic study of oxygen reduction reaction in acid solution using titanium oxide-based catalysts prepared from oxy-titanium tetra-pyrazino-porphyrazine

Hayashi, T., Ishihara, A., Uehara, N., Kohno, Y., Matsuzawa, K., Mitsushima, S. & Ota, K. I. 2015 In : Electrochemistry. 83, 10, p. 807-809 3 p.

Research output: Contribution to journalArticle

Oxygen
Titanium oxides
Catalysts
Titanium
Electrocatalysts
3 Citations

Kinetic study of oxygen reduction reaction on tantalum oxide-based electrocatalysts produced from oxy-tantalum phthalocyanines in acidic media

Uehara, N., Ishihara, A., Nagai, T., Matsumoto, M., Imai, H., Kohno, Y., Matsuzawa, K., Mitsushima, S. & Ota, K. 2015 Nov 10 In : Electrochimica Acta. 182, p. 789-794 6 p.

Research output: Contribution to journalArticle

Electrons
Reaction rates
Tantalum oxides
Oxygen
Hydrogen peroxide
2 Citations

Nano-TaO<inf>x</inf>N<inf>y</inf> particles synthesized from oxy-tantalum phthalocyanine: How to prepare precursors to enhance the oxygen reduction reaction activity after ammonia pyrolysis?

Chisaka, M., Ishihara, A., Uehara, N., Matsumoto, M., Imai, H. & Ota, K. 2015 Aug 28 In : Journal of Materials Chemistry A. 3, 32, p. 16414-16418 5 p.

Research output: Contribution to journalArticle

Tantalum
Oxygen
Catalyst supports
Carbon nanotubes
Pyrolysis

Oxide-based electrocatalysts toward oxygen reduction reaction as non Pt cathodes for PEFC

Uehara, N., Ishihara, A., Imai, H., Matsumoto, M., Arao, M., Ohgi, Y., Kohno, Y., Matsuzawa, K., Mitsushima, S. & Ota, K. I. 2015 ECS Transactions. 36 ed. Electrochemical Society Inc., Vol. 64, p. 23-31 9 p.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Oxygen
Cathodes
Tantalum oxides
Oxides
Electrocatalysts

Oxygen reduction durability and activity of tantalum oxide-based electrocatalysts for cathode of polymer electrolyte fuel cells

Matsuzawa, K., Ishihara, A., Uehara, N., Fujita, Y., Kohno, Y., Matsumoto, M., Ohgi, Y., Mitsushima, S., Imai, H. & Ota, K. I. 2015 ECS Transactions. 17 ed. Electrochemical Society Inc., Vol. 69, p. 3-12 10 p.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Tantalum oxides
Durability
Oxygen
Fuel cells
Cathodes
12 Citations

Synthesis of nano-TaOx oxygen reduction reaction catalysts on multi-walled carbon nanotubes connected via a decomposition of oxy-tantalum phthalocyanine

Ishihara, A., Chisaka, M., Ohgi, Y., Matsuzawa, K., Mitsushima, S. & Ota, K. 2015 Mar 28 In : Physical Chemistry Chemical Physics. 17, 12, p. 7643-7647 5 p.

Research output: Contribution to journalArticle

Tantalum
Carbon nanotubes
Oxygen
Nanotubes
Pyrolysis
4 Citations

Tantalum oxide-based electrocatalysts made from oxy-tantalum phthalocyanines as non-platinum cathodes for polymer electrolyte fuel cells

Uehara, N., Ishihara, A., Matsumoto, M., Imai, H., Kohno, Y., Matsuzawa, K., Mitsushima, S. & Ota, K. 2015 Oct 10 In : Electrochimica Acta. 179, p. 146-153 8 p.

Research output: Contribution to journalArticle

Oxygen
Cathodes
Tantalum oxides
Current density
Tantalum
3 Citations

Titanium-niobium oxides as non-noble metal cathodes for polymer electrolyte fuel cells

Ishihara, A., Tamura, Y., Chisaka, M., Ohgi, Y., Kohno, Y., Matsuzawa, K., Mitsushima, S. & Ota, K. I. 2015 Jul 17 In : Catalysts. 5, 3, p. 1289-1303 15 p.

Research output: Contribution to journalArticle

Oxygen
Cathodes
Oxides
Niobium oxide
Electron energy levels
2014

Assessing the environmental impact of hydrogen energy production

Ota, K., Mitsushima, S., Matsuzawa, K. & Ishihara, A. 2014 Jul 3 Advances in Hydrogen Production, Storage and Distribution. Elsevier Inc., p. 31-42 12 p.

Research output: Chapter in Book/Report/Conference proceedingChapter

Hydrogen
Environmental impact
Energy utilization
Carbon
Water
3 Citations

Determination of Oxygen-Reduction-Reaction Active Sites of Tantalum Oxide-based Cathodes Used for Polymer Electrolyte Fuel Cells

Asada, T., Arao, M., Kubobuchi, K., Mogi, M., Takahashi, Y., Matsumoto, M., Ishihara, A., Ota, K. & Imai, H. 2014 Oct 1 In : Fuel Cells. 14, 5, p. 769-774 6 p.

Research output: Contribution to journalArticle

Oxygen vacancies
Oxygen
Tantalum oxides
Neutron diffraction
Electron diffraction
1 Citations

Enhancement of oxygen reduction activity of titanium nano-oxide-based electrocatalysts for PEFC cathode

Hayashi, T., Ishihara, A., Matsumoto, M., Imai, H., Kohno, Y., Matsuzawa, K., Mitsushima, S. & Ota, K. 2014 ECS Transactions. 3 ed. Electrochemical Society Inc., Vol. 64, p. 247-252 6 p.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Oxygen
Titanium oxides
Titanium
Catalysts
Electrocatalysts
1 Citations

Improvement of the electrocatalytic activity of zirconium oxide-based catalyst for ORR

Okada, Y., Ishihara, A., Arao, M., Matsumoto, M., Imai, H., Kohno, Y., Matsuzawa, K., Mitsushima, S. & Ota, K. I. 2014 ECS Transactions. 3 ed. Electrochemical Society Inc., Vol. 64, p. 231-238 8 p.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Oxygen
Electrocatalysts
Zirconia
Chemical stability
Zirconium

Oxide-based electrocatalysts as precious metal and carbon free cathodes for PEFC

Hamazaki, M., Ishihara, A., Arao, M., Matsumoto, M., Imai, H., Kohno, Y., Matsuzawa, K., Mitsushima, S. & Ota, K. 2014 ECS Transactions. 3 ed. Electrochemical Society Inc., Vol. 64, p. 239-246 8 p.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Oxides
Cathodes
Oxygen
Electrocatalysts
Oxygen vacancies
1 Citations

Transition Metal Oxides, Carbides, Nitrides, Oxynitrides, and Carbonitrides for O2 Reduction Reaction Electrocatalysts for Acid PEM Fuel Cells

Ishihara, A., Imai, H. & Ota, K. I. 2014 May 19 Non-Noble Metal Fuel Cell Catalysts. Wiley Blackwell, p. 183-204 22 p.

Research output: Chapter in Book/Report/Conference proceedingChapter

Oxygen
Oxides
Catalyst activity
Cathodes
Catalysts
2013
1 Citations

Activity of tantalum oxide-based electrocatalysts toward oxygen reduction reaction for PEFC

Uehara, N., Ishihara, A., Kohno, Y., Matsuzawa, K., Mitsushima, S. & Ota, K. I. 2013 ECS Transactions. 1 ed. Electrochemical Society Inc., Vol. 58, p. 1217-1223 7 p.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Oxygen
Cathodes
Tantalum oxides
Ball milling
Catalyst supports

Advanced study of transition metal oxidebased cathode for PEFCS

Ota, K., Matsuzawa, K., Mitsushima, S. & Ishihara, A. 2013 EFC 2013 - Proceedings of the 5th European Fuel Cell Piero Lunghi Conference. ENEA, p. 71-72 2 p.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Cathodes
Oxides
Catalyst activity
Cost reduction
Transition metals
28 Citations

Emergence of oxygen reduction activity in partially oxidized tantalum carbonitrides: Roles of deposited carbon for oxygen-reduction-reaction-site creation and surface electron conduction

Ishihara, A., Tamura, M., Ohgi, Y., Matsumoto, M., Matsuzawa, K., Mitsushima, S., Imai, H. & Ota, K. I. 2013 Sep 19 In : Journal of Physical Chemistry C. 117, 37, p. 18837-18844 8 p.

Research output: Contribution to journalArticle

Oxygen
Carbon nitride
Tantalum
Carbon
Tantalum oxides
4 Citations

Enhancement of oxygen reduction activity of zirconium oxide-based cathode for PEFC

Yin, S., Ishihara, A., Kohno, Y., Matsuzawa, K., Mitsushima, S., Ota, K. I., Matsumoto, M. & Imai, H. 2013 ECS Transactions. 1 ed. Electrochemical Society Inc., Vol. 58, p. 1489-1494 6 p.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Oxygen
Zirconium
Cathodes
Protective atmospheres
Voltammetry
19 Citations

Factors for improvements of catalytic activity of zirconium oxide-based oxygen-reduction electrocatalysts

Ohgi, Y., Ishihara, A., Matsuzawa, K., Mitsushima, S., Ota, K. I., Matsumoto, M. & Imai, H. 2013 Apr 2 In : Journal of the Electrochemical Society. 160, 2

Research output: Contribution to journalArticle

Zirconium
Oxygen
Carbon nitride
Oxidation
Carbon
3 Citations

Immersed effects of Ta and Zr compounds on activity of oxygen reduction reaction in sulfuric acid

Matsuzawa, K., Nozawa, K., Yamauchi, K., Ishihara, A., Mitsushima, S. & Ota, K. I. 2013 Mar 15 In : Journal of Power Sources. 226, p. 16-19 4 p.

Research output: Contribution to journalArticle

Sulfuric acid
Oxygen
Catalyst activity
1 Citations

Improving ORR activity of group 4 and 5 metal oxide-based cathodes for PEFCs

Ishihara, A., Yin, S., Suito, K., Uehara, N., Okada, Y., Kohno, Y., Matsuzawa, K., Mitsushima, S., Chisaka, M., Ohgi, Y., Matsumoto, M., Imai, H. & Ota, K. I. 2013 ECS Transactions. 1 ed. Electrochemical Society Inc., Vol. 58, p. 1495-1500 6 p.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Cathodes
Oxides
Oxygen
Metals
Nitridation

Metal Oxide-based compounds as electrocatalysts for Oxygen reduction reaction

Ota, K. I. & Ishihara, A. 2013 Lecture Notes in Energy. Vol. 9, p. 391-416 26 p. (Lecture Notes in Energy; vol. 9)

Research output: Chapter in Book/Report/Conference proceedingChapter

Oxides
Oxygen
Catalysts
Platinum
Cathodes

Nano-sized titanium oxides as electrocatalyst for oxygen reduction reaction toward PEFC

Suito, K., Ishihara, A., Hayashi, T., Matsumoto, M., Arao, M., Kohno, Y., Matsuzawa, K., Imai, H., Mitsushima, S. & Ota, K. 2013 ECS Transactions. 47 ed. Electrochemical Society Inc., Vol. 58, p. 1-7 7 p.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Titanium oxides
Oxygen
Cathodes
Carbon nitride
Electrocatalysts
23 Citations

Oxygen reduction reaction activity of nitrogen-doped titanium oxide in acid media

Chisaka, M., Ishihara, A., Suito, K., Ota, K. I. & Muramoto, H. 2013 Jan 15 In : Electrochimica Acta. 88, p. 697-707 11 p.

Research output: Contribution to journalArticle

Oxygen
Heat treatment
Temperature
Nitrogen
Gases

Stabilization and activation of zirconium oxide based electrocatalysts as PEFC cathode by re-heat treatment

Okada, Y., Ishihara, A., Matsumoto, M., Arao, M., Imai, H., Kohno, Y., Matsuzawa, K., Mitsushima, S. & Ota, K. 2013 ECS Transactions. 1 ed. Electrochemical Society Inc., Vol. 58, p. 1225-1231 7 p.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Electrocatalysts
Zirconia
Durability
Heat treatment
Stabilization
14 Citations

Synthesis of carbon-supported titanium oxynitride nanoparticles as cathode catalyst for polymer electrolyte fuel cells

Chisaka, M., Ishihara, A., Ota, K. I. & Muramoto, H. 2013 Dec 15 In : Electrochimica Acta. 113, p. 735-740 6 p.

Research output: Contribution to journalArticle

Nanoparticles
Carbon
Titanium oxides
Fuel cells
Cathodes
1 Citations

Zirconium oxide-based cathode prepared by partial oxidation of carbonitrides as non-precious metal cathode for polymer electrolyte fuel cells

Ota, K. I., Ohgi, Y., Matsuzawa, K., Mitsushima, S. & Ishihara, A. 2013 Jan 1 ECS Transactions. 12 ed. Electrochemical Society Inc., Vol. 53, p. 1-8 8 p.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Carbon nitride
Cathodes
Zirconium
Fuel cells
Electrolytes
2012
2 Citations

Catalytic activity and stability of Ta compounds for oxygen reduction reaction

Mitsushima, S., Fujita, Y., Ishihara, A., Ohgi, Y., Matsuzawa, K., Matsumoto, M., Arao, M., Imai, H., Kohno, Y. & Otaa, K. 2012 Dec 1 ECS Transactions. 2 ed. Vol. 50, p. 1823-1829 7 p.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Oxygen
Electrocatalysts
Chronoamperometry
Carbon nitride
Tantalum
4 Citations

Highly active titanium oxide-based catalyst for oxygen reduction reaction for PEFC

Suito, K., Ishihara, A., Arao, M., Matsumoto, M., Imai, H., Kohno, Y., Matsuzawa, K., Mitsushima, S. & Ota, K. 2012 Dec 1 ECS Transactions. 2 ed. Vol. 50, p. 1777-1783 7 p.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Catalysts
Oxygen
Titanium oxides
Platinum
Pyrolysis
2 Citations

ORR activity of Nb oxide based catalyst prepared from Nb compound including C and N

Hara, K., Ishihara, A., Matsumoto, M., Arao, M., Imai, H., Kohno, Y., Matsuzawa, K., Mitsushima, S. & Ota, K. 2012 Dec 1 ECS Transactions. 2 ed. Vol. 50, p. 1769-1775 7 p.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Catalysts
Oxides
Carbon nitride
Oxygen
Metals
29 Citations

Oxygen reduction reaction on tantalum oxide-based catalysts prepared from TaC and TaN

Ohgi, Y., Ishihara, A., Matsuzawa, K., Mitsushima, S., Ota, K. I., Matsumoto, M. & Imai, H. 2012 Apr 30 In : Electrochimica Acta. 68, p. 192-197 6 p.

Research output: Contribution to journalArticle

Oxygen
Tantalum carbide
Nitrides
Oxidation
Tantalum oxides
4 Citations

Surface reaction analysis of tantalum-oxide oxygen-reduction catalysts by using X-ray photoelectron spectroscopy

Matsumoto, M., Miyazaki, T., Fujieda, S., Ishihara, A., Ota, K. I. & Imai, H. 2012 ECS Transactions. 2 ed. Vol. 50, p. 1759-1767 9 p.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

X rays
Oxygen
Photoelectron spectroscopy
Catalysts
X ray photoelectron spectroscopy
8 Citations

Synthesis of highly active Zr oxide-based oxygen reduction electrocatalysts as PEFC cathode

Yin, S., Ishihara, A., Kohno, Y., Matsuzawa, K., Mitsushima, S., Ota, K. I., Matsumoto, M., Arao, M. & Imai, H. 2012 Dec 1 ECS Transactions. 2 ed. Vol. 50, p. 1785-1790 6 p.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Oxygen
Zirconium
Cathodes
Protective atmospheres
Oxides
2 Citations

Transition metal oxide based materials for cathode of polymer electrolyte fuel cells

Ota, K., Ohgi, Y., Matsuzawa, K., Mitsushima, S. & Ishihara, A. 2012 Nov 19 ECS Transactions. 2 ed. Vol. 45, p. 27-33 7 p.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Oxides
Cathodes
Carbon nitride
Fuel cells
Catalyst activity
2011
23 Citations

Carbon nanowalls as platinum support for fuel cells

Chul Shin, S., Yoshimura, A., Matsuo, T., Mori, M., Tanimura, M., Ishihara, A., Ota, K. I. & Tachibana, M. 2011 Nov 15 In : Journal of Applied Physics. 110, 10, 104308

Research output: Contribution to journalArticle

Catalyst supports
Platinum
Nanoparticles
Carbon
Electronic properties
2 Citations
Oxygen
Catalyst activity
Reactive sputtering
Tantalum oxides
Tantalum
1 Citations

Catalytic activity for oxygen reduction reaction on tantalum oxide-based compounds (2) active sites of taon thin film catalysts and role of carbon

Ishihara, A., Kikuchi, A., Ohgi, Y., Matsuzawa, K., Mitsushima, S., Ota, K. I., Matsumoto, M. & Imai, H. 2011 Oct 1 In : Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals. 75, 10, p. 552-556 5 p.

Research output: Contribution to journalArticle

Oxygen
Carbon
Nitrogen
Adsorption
Thin films
32 Citations

Development of group 4 and 5 metal oxide-based cathodes for polymer electrolyte fuel cell

Ota, K. I., Ohgi, Y., Nam, K. D., Matsuzawa, K., Mitsushima, S. & Ishihara, A. 2011 Jun 15 In : Journal of Power Sources. 196, 12, p. 5256-5263 8 p.

Research output: Contribution to journalArticle

Carbon nitride
Oxides
Oxygen
Defects
Ionization potential

Factors for improvements of catalytic activity for zirconium oxide-based oxygen-reduction electrocatalysts

Ohgi, Y., Ishihara, A., Matsuzawa, K., Mitsushima, S., Ota, K., Matsumoto, M. & Imai, H. 2011 Dec 1 ECS Transactions. 1 ed. Vol. 41, p. 1225-1247 23 p.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Oxygen vacancies
Zirconia
Catalyst activity
Defects
Oxides

Origin of oxygen reduction activity on tantalum oxide-based compounds as non-platinum cathodes for pefc

Ishihara, A., Ohgi, Y., Matsuzawa, K., Mitsushima, S., Ota, K., Matsumoto, M. & Imai, H. 2011 EFC 2011 - Proceedings of the 4th European Fuel Cell Piero Lunghi Conference and Exhibition. ENEA, p. 275-276 2 p.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Oxygen
Oxygen vacancies
Cathodes
Oxidation
Carbon
9 Citations
Oxygen
Catalyst activity
Carbon nitride
Tantalum
Fuel cells
1 Citations

Pt-Ir-SnO 2/C electrocatalysts for ethanol oxidation in acidic media

Zhao, L., Mitsushima, S., Ishihara, A., Matsuzawa, K. & Ota, K. I. 2011 Dec 1 In : Cuihua Xuebao/Chinese Journal of Catalysis. 32, 12, p. 1856-1863 8 p.

Research output: Contribution to journalArticle

Catalysts
Ethanol
Oxidation
Direct ethanol fuel cells (DEFC)
Catalyst selectivity
6 Citations

Pt-Ir-SnO 2/C electrocatalysts for ethanol oxidation in acidic media

Zhao, L., Mitsushima, S., Ishihara, A., Matsuzawa, K. & Ota, K. I. 2011 Nov 1 In : Chinese Journal of Catalysis. 32, 11-12, p. 1856-1863 8 p.

Research output: Contribution to journalArticle

Catalysts
Ethanol
Oxidation
Direct ethanol fuel cells (DEFC)
Catalyst selectivity
1 Citations

Quantitative analysis of electrooxidation products on platinum for direct ethanol fuel cell

Matsuzawa, K., Takahashi, T., Ishihara, A., Mitsushima, S. & Ota, K. I. 2011 May 1 In : Electrochemistry. 79, 5, p. 419-423 5 p.

Research output: Contribution to journalArticle

Electrooxidation
Direct ethanol fuel cells (DEFC)
Byproducts
Platinum
Chemical analysis