Showa Denko K.k.

Japan Science and Technology Agency

Yokohama National University

Panasonic Corporation

Kenichiro Ota

Ryuji Monden

Yasuaki Wakizaka

Akimitsu Ishihara

Takuya Imai

Toshikazu Shishikura

Kunchan Lee

Shigenori Mitsushima

Nobuyuki Kamiya

Takaiki Nomura

Michikazu Hara

Kazuhito Hato

Takahiro Suzuki

Kenichi Tokuhiro

Takashi Sato

Chunfu Yu

Masaki Horikita

Kazunori Ichioka

Ryoko Konta

Makoto Hamazaki

Liu Yan

Kazunari Doumen

Yoshinori Yamato

Shigenori Mittsushima

An object of the invention is to provide an oxygen reduction catalyst composed of a titanium oxynitride having high oxygen reduction capacity. The oxygen reduction catalyst of the invention is a titanium oxynitride that has a nitrogen element content of 8.0 to 15 mass %, has a crystal structure of anatase titanium dioxide in a powder X-ray diffraction measurement, and has a signal intensity ratio N&#x2014;Ti&#x2014;N/O&#x2014;Ti&#x2014;N in an X-ray photoelectron spectroscopic analysis of in the range of 0.35 to 0.70.

Oxygen reduction catalyst

The present invention provides a novel oxygen reduction catalyst having a good stability and a high oxygen reduction performance. The oxygen reduction catalyst includes: a conductive oxide; and an oxide(s), having oxygen holes and provided at least on the surface of the conductive oxide, of at least one or more transition metals selected from the group consisting of Ti, Zr, Nb and Ta.

Oxygen reduction catalyst and production method therefor

A semiconductor material of the present invention is a semiconductor material including an oxynitride containing at least one element selected from the Group 4 elements and Group 5 elements. In the oxynitride, part of at least one selected from oxygen and nitrogen is substituted with carbon. Nb is preferable as the Group 5 element.

Semiconductor material, optical hydrogen generating device using same, and method of producing hydrogen

The invention provides catalysts that are not corroded in acidic electrolytes or at high potential and have excellent durability and high oxygen reducing ability. The catalyst includes a metal element M, carbon, nitrogen and oxygen, wherein the catalyst shows peaks at 1340 cmto 1365 cmand at 1580 cmto 1610 cmas analyzed by Raman spectroscopy and the metal element M is one selected from titanium, iron, niobium, zirconium and tantalum. The catalysts of the invention are stable and are not corroded in acidic electrolytes or at high potential, have high oxygen reducing ability and are inexpensive compared to platinum. Fuel cells having the catalysts are therefore relatively inexpensive and have high performance.

Catalyst, production process therefor, and use thereof

Provided is a process for producing a fuel cell electrode catalyst having high catalytic activity which uses a transition metal, e.g., titanium, which process comprises thermal treatment at relatively low temperature, i.e., not including thermal treatment at high temperature (calcining) step. The process for producing a fuel cell electrode catalyst comprises a step (1) of mixing at least a transition metal-containing compound, a nitrogen-containing organic compound and a solvent to provide a catalyst precursor solution; a step (2) of removing the solvent from the catalyst precursor solution; and a step (3) of thermally treating a solid residue obtained in the step (2) at a temperature of 500 to 1100&#xb0; C. to provide an electrode catalyst; wherein the transition metal-containing compound is partly or wholly a compound comprising at least one transition metal element (M1) selected from the group 4 and 5 elements of the periodic table as a transition metal element.

Process for producing fuel cell electrode catalyst, process for producing transition metal oxycarbonitride, fuel cell electrode catalyst and uses thereof

[Object] The invention provides catalysts that are not corroded in acidic electrolytes or at high potential and have excellent durability and high oxygen reducing ability. [Solution] A catalyst of the invention includes a metal oxycarbonitride that contains titanium and at least one metal (hereinafter, also referred to as 'metal M' or simply 'M') selected from silver, calcium, strontium, yttrium, ruthenium, lanthanum, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium.

Catalyst, production process therefor and use thereof

[Problem] To provide a catalyst which has high oxygen reduction activity, also has excellent durability, and is inexpensive and excellent in electric power generation cost as compared with noble metal catalysts such as platinum. [Solution to problem] A catalyst for a polymer electrolyte fuel cell, including a graphitized carbon powder and a niobium oxycarbonitride or a titanium oxycarbonitride as an active substance, and a polymer electrolyte fuel cell using the catalyst.

Catalyst for fuel cell and polymer electrolyte fuel cell using the same

It is an object of the present invention to provide a production process which can produce a fuel cell catalyst having excellent durability and high oxygen reducing activity. The process for producing a fuel cell catalyst including a metal-containing oxycarbonitride of the present invention includes a grinding step for grinding the oxycarbonitride using a ball mill, wherein the metal-containing oxycarbonitride is represented by a specific compositional formula; balls in the ball mill have a diameter of 0.1 to 1.0 mm; the grinding time using the ball mill is 1 to 45 minutes; the rotating centrifugal acceleration in grinding using the ball mill is 2 to 20 G; the grinding using the ball mill is carried out in such a state that the metal-containing oxycarbonitride is mixed with a solvent containing no oxygen atom in the molecule; and when the ball mill is a planetary ball mill, the orbital centrifugal acceleration mill is 5 to 50 G.

Process for producing fuel cell catalyst, fuel cell catalyst obtained by production process, and uses thereof

A corrosion-resistant electrode catalyst for oxygen reduction includes a main catalyst composed of at least one transition metal oxide selected from oxygen-deficient ZrO, TaO, NbO, TiO, VO, MoO, and WOand a co-catalyst composed of gold. The electrode catalyst is used in contact with an acidic electrolyte at a potential at least 0.4 V higher than the reversible hydrogen electrode potential. The catalyst may be used, for example, in such a form that the transition metal oxide in the form of fine particles and gold in the form of fine particles, or fine particles including fine gold particles coated with the transition metal oxide are dispersed on a catalyst carrier which is an electron conductive powder. This electrode catalyst is suitable as an electrode catalyst for an electrochemical system using an acidic electrolyte in the fields of water electrolysis, inorganic/organic electrolysis, fuel cells, etc.

Corrosion resistant metal oxide electrode catalyst for oxygen reduction

An electrode catalyst that maintains catalytic activity under conditions of an electrode potential as high as 0.4 V or above and exhibits improved stability. The metal oxynitride electrode catalyst is composed of an oxynitride containing at least one transition metal element selected from the group consisting of La, Ta, Nb, Ti, and Zr, the metal oxynitride electrode catalyst being used at a potential of 0.4 V or higher relative to the reversible hydrogen electrode potential in an acidic electrolyte. The metal oxynitride electrode catalyst is useful as an electrode catalyst for electrochemical systems used in acidic electrolytes in the fields of water electrolysis, organic electrolysis, fuel cells, etc.

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Koganei, Japan

Kenichiro Ota