Kabushiki Kaisha Toshiba

Intematix Corporation

Itsuko Mizutani

Yoshihiko Nakano

Wu Mei

Taishi Fukazawa

Tsuyoshi Kobayashi

Yi-Qun Li

Shinji Aoki

Takahiro Sato

Mina Farag

Masaaki Yamamoto

Hiroyasu Sumino

A methanol oxidation catalyst comprises a material of composition:PtMTain which Pt is platinum, Ta is tantalum, M is an element includes at least one selected from the group consisting of V (vanadium), W (tungsten), Ni (nickel) and Mo (molybdenum), x is 40 to 98 at. %, z is 1.5 to 55 at. %, and u is 0.5 to 40 at. %. To maximize catalytic activity the material is preferably in the form of nanoparticles. The values of x, z and u are selected such that the element exhibits X-ray photoelectron spectroscopy peaks derived from an oxygen bond and a metal bond in which a peak area derived from the oxygen bond is twice or less of a peak area derived from the metal bond.

Methanol oxidation catalyst

A catalyst is provided and includes fine catalyst particles of a composition represented by formula (1): PtRuTaT, in which T is at least one element selected from the group consisting of Hf, W, Ni, and V; u, x, y, and z are 10 to 98.9 atm %, 0.1 to 50 atm %, 0.5 to 35 atm %, and 0.5 to 35 atm %, respectively, or formula (2): PtRuTaT, in which T is at least one element selected from the group consisting of Ct, Mo, Nb, Zr, and T; u, x, y, and z are 40 to 70 atm %, 0.1 to 50 atm %, 0.5 to 15 atm %, and 0.5 to 15 atm %, respectively.

Catalyst, method for producing catalyst, membrane electrode assembly, and fuel cell

There is provided a catalyst for a fuel cell, which simultaneously realizes excellent catalytic activity and catalytic stability. The catalyst for a fuel cell comprises a fine particle of a metal represented by formula:PtRuSiT1wherein T1 represents at least one element selected from the group consisting of nickel (Ni), tungsten (W), vanadium (V), and molybdenum (Mo); x=30 to 90 atomic %; y=0 to 50 atomic %; z=0.5 to 20 atomic %; and u=0.5 to 40 atomic %, or comprises a fine particle of a metal represented by formula:PtRuSiT2wherein T2 represents at least one element selected from the group consisting of hafnium (Hf), tin (Sn), zirconium (Zr), niobium (Nb), titanium (Ti), tantalum (Ta), chromium (Cr), and aluminum (Al); x=30 to 90 atomic %; y=0 to 50 atomic %; z=0.5 to 20 atomic %; and u=0.5 to 40 atomic %.

Catalyst for polymer solid electrolyte fuel cell, membrane electrode assembly, and fuel cell

This invention provides a process for producing a membrane electrode assembly which has high and stable catalytic activity, and suppressed deterioration in catalytic activity during operation, and can prevent a deterioration in performance attributable to a structural factor of the membrane electrode assembly. The process comprises the step of, after the washing/removing step, drying the catalyst electrode in an atmosphere having a lower oxygen partial pressure than the air. The anode/cathode is a covered catalyst electrode having a structure formed by supporting/depositing a catalytically active material composed mainly of platinum/ruthenium subjected to the potential holding step, the washing/removing step, and the drying step, on a porous electroconductive carrier to cover at least a part of the porous electroconductive carrier with the ion conductive material.

Process for producing membrane electrode assembly, and fuel cell using the membrane electrode assembly produced by the process

A methanol oxidation catalyst is provided, which includes nanoparticles having a composition represented by the following formula 1:PtRuTQ&#x2003;&#x2003;formula 1 In the formula 1, the T-element is at least one selected from a group consisting of Mo, W and V and the Q-element is at least one selected from a group consisting of Nb, Cr, Zr and Ti, x is 40 to 90 at. %, y is 0 to 9.9 at. %, z is 3 to 70 at. % and u is 0.5 to 40 at. %. The area of the peak derived from oxygen bond of T-element is 80% or less of the area of the peak derived from metal bond of T-element in a spectrum measured by an X-ray photoelectron spectral method.

The present invention provides a catalyst having high activity and excellent stability, a process for preparation of the catalyst, a membrane electrode assembly, and a fuel cell. The catalyst of the present invention comprises an electronically conductive support and catalyst fine particles. The catalyst fine particles are supported on the support and are represented by the formula (1): PtRuGeT(1). In the formula, u, x, y and z mean 30 to 60 atm %, 20 to 50 atm %, 0.5 to 20 atm % and 0.5 to 40 atm %, respectively. When the element represented by T is Al, Si, Ni, W, Mo, V or C, the content of the T-element's atoms connected with oxygen bonds is not more than four times as large as that of the T-element's atoms connected with metal bonds on the basis of X-ray photoelectron spectrum (XPS) analysis. When the T-element is Ti, Hf, Sn, Ta, Zr or Nb, the content of the T-element's atoms connected with metal bonds is not more than twice as large as that of the T-element's atoms connected with oxygen bonds on the basis of XPS analysis.

Fuel cell catalyst, process for preparation of the same, and membrane electrode assembly and fuel cell employing the catalyst

A catalyst includes a conductive carrier and catalyst particles. The catalyst particles are supported on the conductive carrier and have a composition represented by formula 1, below. An area of a peak derived from a metal bond of a T-element is 15% or more of an area of a peak derived from an oxygen bond of the T-element in a spectrum obtained by X-ray photoelectron spectroscopic method.PtRuT&#x2003;&#x2003;(1)where the T-element is at least one element selected from the group consisting of V, Nb and Hf, x is 30 to 60 at. %, y is 20 to 50 at. % and z is 5 to 50 at. %.

Catalyst, membrane electrode assembly and fuel cell

A methanol oxidation catalyst is provided, which includes nanoparticles having a composition represented by the following formula (1):PtRuMoT&#x2003;&#x2003;(1) In the formula (1), the T-element is at least one selected from the group consisting of W and V, x is 20 to 80 at. %, y is 10 to 60 at. %, z is 1 to 30 at. % and u is 1 to 30 at. %. The area of the peak derived from oxygen bond of T-element is 80% or less of the area of the peak derived from metal bond of T-element in a spectrum measured by an X-ray photoelectron spectral method.

Growing community of inventors

Yokohama, Japan

Itsuko Mizutani