Showa Denko K.k.

Tokyo Institute of Technology

Yokohama National University

Kunchan Lee

Ryuji Monden

Takashi Sato

Takuya Imai

Yasuaki Wakizaka

Masaki Horikita

Chunfu Yu

Hiroshi Takahashi

Kenichiro Ota

Tomoya Kitagawa

Yoshinori Abe

Kazuo Furuya

Yuji Ito

Yoshishige Okuno

Toshikazu Shishikura

Akimitsu Ishihara

Kazunori Ichioka

Ryoko Konta

Kunning Zhu

Keiko Waki

Masashi Takano

Suguru Sakaguchi

Yoshinori Yamato

Masabumi Kusaka

Provided are an oxygen reduction catalyst having a high electrode potential under a fuel cell operating environment, an electrode containing the oxygen reduction catalyst, a membrane electrode assembly in which a cathode is the electrode, and a fuel cell including the membrane electrode assembly. The oxygen reduction catalyst used here contains cobalt, sulfur, and oxygen as elements, has a CoScubic structure in powder X-ray diffractometry, and having an S&#x2014;Co/S&#x2014;O peak area ratio of 6 to 15 in an S2p spectrum in X-ray photoelectron spectroscopic analysis.

Oxygen reduction catalyst, electrode, membrane electrode assembly, and fuel cell

Provided are an oxygen reduction catalyst having a high electrode potential under a fuel cell operating environment, an electrode containing the oxygen reduction catalyst, a membrane electrode assembly in which a cathode is the electrode, and a fuel cell including the membrane electrode assembly. The oxygen reduction catalyst used here contains cobalt, sulfur, and oxygen as elements, has a CoS hexagonal structure in powder X-ray diffractometry, and having an S&#x2014;Co/S&#x2014;O peak area ratio of 2.1 to 8.9 in an S2p spectrum in X-ray photoelectron spectroscopic analysis.

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 relates to an oxygen reduction catalyst, an electrode, a membrane electrode assembly, and a fuel cell, and the oxygen reduction catalyst is an oxygen reduction catalyst containing substituted CoS, in which the substituted CoShas a cubic crystal structure, the oxygen reduction catalyst contains the substituted CoSwithin 0.83 nm from the surface thereof, and the substituted CoShas at least one substitutional atom selected from the group consisting of Cr, Mo, Mn, Tc, Re, Rh, Cu, and Ag in some of Co atom sites.

A catalyst carrier, an electrode catalyst, an electrode including the catalyst, a membrane electrode assembly including the electrode, a fuel cell including the membrane electrode assembly, and a method for producing the catalyst carrier. The catalyst carrier includes a carbon material having a chain structure including a chain of carbon particles. The catalyst carrier contains a titanium compound-carbon composite particle in which carbon encloses a titanium compound particle. The molar ratios of a carbon element, a nitrogen element, and an oxygen element to a titanium element taken as 1 in the catalyst carrier are more than 0 and 50 or less, more than 0 and 2 or less, and more than 0 and 3 or less, respectively.

Catalyst carrier, method for producing catalyst carrier, and use of catalyst carrier

Provided is a process for producing a fuel cell electrode catalyst with high catalytic activity that is alternative to a noble metal catalyst, through a heat treatment at a relatively low temperature. A process for producing a fuel cell electrode catalyst includes a step (I) of obtaining a catalyst precursor, including a step (Ia) of mixing at least a metal compound (1), a nitrogen-containing organic compound (2), and a fluorine-containing compound (3), and a step (II) of heat-treating the catalyst precursor at a temperature of 500 to 1300&#xb0; C. to obtain an electrode catalyst, a portion or the entirety of the metal compound (1) being a compound containing an atom of a metal element M1 selected from the group consisting of iron, cobalt, chromium, nickel, copper, zinc, titanium, niobium and zirconium, and at least one of the compounds (1), (2) and (3) containing an oxygen atom.

Process for producing a fuel cell electrode catalyst, fuel cell electrode catalyst and use thereof

A method for producing a fuel cell electrode catalyst, including a step (I) of bringing an aqueous solution of a transition metal compound (1) into contact with ammonia and/or ammonia water to generate a precipitate (A) containing an atom of the transition metal, a step (II) of mixing at least the precipitate (A), an organic compound (B), and a liquid medium (C) to obtain a catalyst precursor liquid, and a step (IV) of subjecting the solid in the catalyst precursor liquid to heat treatment at a temperature of 500 to 1200&#xb0; C. to obtain an electrode catalyst; a portion or the entirety of the transition metal compound (1) being a compound containing a transition metal element of group 4 or group 5 of the periodic table; and the organic compound (B) being at least one selected from sugars and the like.

Method for producing fuel cell electrode catalyst

A catalyst carrier, an electrode catalyst, an electrode including the catalyst, a membrane electrode assembly including the electrode, and a fuel cell including the membrane electrode assembly. The catalyst carrier includes a carbon material having a chain structure including a chain of carbon particles, and an oxide-carbon composite particle in which a carbon particle encloses a particle of an oxide of a group IV element on the periodic table, the oxide-carbon composite particle being contained in the carbon material. The catalyst carrier has a BET specific surface area of 450 to 1100 m/g.

Catalyst carrier and method for producing the same

A catalyst carrier, an electrode catalyst, an electrode including the catalyst, a membrane electrode assembly including the electrode, and a fuel cell including the membrane electrode assembly. The catalyst carrier includes a carbon material having a chain structure including a chain of carbon particles and an alumina-carbon composite particle in which a carbon particle encloses an alumina particle, the alumina-carbon composite particle is contained in the carbon material, and the catalyst carrier has a BET specific surface area of 450 to 1100 m/g.

A method is provided for producing a platinum alloy-containing fuel cell electrode catalyst with high activity which is suited for its industrial mass-production. The method for producing a fuel cell electrode catalyst includes a step of preparing a dispersion in which particles of a fuel cell electrode catalyst precursor including a platinum alloy is dispersed in an electrolyte solution, and a step of alternately subjecting the dispersion to bubbling with an oxidizing gas and to bubbling with an inert gas or a reducing gas.

A catalyst carrier production process includes a step (a) of mixing a transition metal compound (1), a nitrogen-containing organic compound (2), and a solvent to provide a catalyst carrier precursor solution; a step (b) of removing the solvent from the catalyst carrier precursor solution; and a step (c) of thermally treating a solid residue obtained in the step (b) at a temperature of 500 to 1100&#xb0; C. to provide a catalyst carrier; wherein the transition metal compound (1) is partly or wholly a compound including a transition metal element (M1) selected from the group 4 and 5 elements of the periodic table as a transition metal element; and at least one of the transition metal compound (1) and the nitrogen-containing organic compound (2) includes an oxygen atom.

Process for producing catalyst carrier, process for producing composite catalyst, composite catalyst, and fuel cell using same

In a direct-liquid fuel cell supplied directly with a liquid fuel, a process for producing an electrode catalyst for a direct-liquid fuel cell is provided which is capable of suppressing decrease in cathode potential caused by liquid fuel crossover and providing an inexpensive and high-performance electrode catalyst for a direct-liquid fuel cell. The process for producing an electrode catalyst for a direct-liquid fuel cell includes Step A of mixing at least a transition metal-containing compound with a nitrogen-containing organic compound to obtain a catalyst precursor composition, and Step C of heat-treating the catalyst precursor composition at a temperature of from 500 to 1100&#xb0; C. to obtain an electrode catalyst, wherein part or entirety of the transition metal-containing compound includes, as a transition metal element, at least one transition metal element M1 selected from Group IV and Group V elements of the periodic table.

Process for producing catalyst for direct-liquid fuel cell, catalyst produced by the process and uses thereof

A method for producing a fuel cell electrode catalyst including a metal element selected from aluminum, chromium, manganese, iron, cobalt, nickel, copper, strontium, yttrium, tin, tungsten, and cerium and having high catalytic activity through heat treatment at comparatively low temperature. The method including: a step (1) of mixing at least a certain metal compound (), a nitrogen-containing organic compound (), and a solvent to obtain a catalyst precursor solution, a step (2) of removing the solvent from the catalyst precursor solution, and a step (3) of heat-treating a solid residue, obtained in the step (2), at a temperature of 500 to 1100&#xb0; C. to obtain an electrode catalyst; a portion or the entirety of the metal compound () being a compound containing, as the metal element, a metal element Mselected from aluminum, chromium, manganese, iron, cobalt, nickel, copper, strontium, yttrium, tin, tungsten, and cerium.

Method for producing fuel cell electrode catalyst, fuel cell electrode catalyst, and uses thereof

A catalyst carrier production process includes a step (a) of mixing a transition metal compound (), a nitrogen-containing organic compound (), and a solvent to provide a catalyst carrier precursor solution; a step (b) of removing the solvent from the catalyst carrier precursor solution; and a step (c) of the thermally treating a solid residue obtained in the step (b) at a temperature of 500 to 1100&#xb0; C. to provide a catalyst carrier; wherein the transition metal compound () is partly or wholly a compound including a transition metal element (M) selected from the group 4 and 5 elements of the periodic table as a transition metal element; and at least one of the transition metal compound () and the nitrogen-containing organic compound () includes an oxygen atom.

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

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Tokyo, Japan

Kunchan Lee