摘要:
A methanol oxidation catalyst comprises a material of composition: PtxMzTau in 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.
摘要:
A methanol oxidation catalyst is provided, which includes nanoparticles having a composition represented by the following formula 1: PtxRuyTzQu 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.
摘要:
A methanol oxidation catalyst is provided, which includes nanoparticles having a composition represented by the following formula (1): PtxRuyMozTu (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.
摘要:
A methanol oxidation catalyst comprises a material of composition: PtxMzTau in 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 mater al 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.
摘要:
A methanol oxidation catalyst is provided, which includes nanoparticles having a composition represented by the following formula (1): PtxRuyMozTu (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.
摘要:
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.
摘要:
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.
摘要:
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. PtxRuyTz (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. %.
摘要:
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): PtuRuxGeyTz (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.
摘要:
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): PtuRuxGeyTz (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.