Methanol oxidation catalyst
View Patent ↗A methanol oxidation catalyst is provided, which includes nanoparticles having a composition represented by the following formula (1): Pt x Ru y Mo z T u (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.
1. A methanol oxidation catalyst comprising:
nanoparticles having a composition represented by the following formula 1:
Pt x Ru y Mo z T u formula 1
where T 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. %,
wherein the catalyst shows a peak derived from an oxygen bond of T and a peak derived from a metal bond of T in a spectrum measured by an X-ray photoelectron spectral method, and wherein the area of the peak derived from the oxygen bond of T is 80% or less of the area of the peak derived from the metal bond of T.
2. The methanol oxidation catalyst according to claim 1 , wherein T is W.
3. The methanol oxidation catalyst according to claim 2 , wherein z is 2 to 20 at. %.
4. The methanol oxidation catalyst according to claim 2 , wherein u is 2 to 20 at. %.
5. The methanol oxidation catalyst according to claim 1 , wherein a part of the Pt and Ru is substituted with a noble metal other than Pt and Ru.
6. The methanol oxidation catalyst according to claim 5 , wherein the noble metal other than Pt and Ru is at least one selected from a group consisting of Rh, Os, Ir, Pd, Ag and Au.
7. The methanol oxidation catalyst according to claim 1 , further comprising 25 at. % or less of oxygen.
8. The methanol oxidation catalyst according to claim 1 , wherein a content of at least one impurity element selected from the group consisting of P, S and Cl is 0.1 at. % or less.
9. The methanol oxidation catalyst according to claim 1 , wherein the nanoparticles have an average particle diameter of 10 nm or less.
10. The methanol oxidation catalyst according to claim 9 , wherein the nanoparticles have an average particle diameter of 0.5 nm or more.
11. The methanol oxidation catalyst according to claim 1 , further comprising a conductive support carrying the nanoparticles.
12. The methanol oxidation catalyst according to claim 11 , wherein the conductive support is selected from a group consisting of a carbon material and a conductive ceramics material.
13. The methanol oxidation catalyst according to claim 12 , wherein the wherein the conductive support is a carbon material that is in the form of a fiber, a tube, or a coil.
14. A methanol oxidation catalyst comprising:
nanoparticles having a composition represented by the following formula 1:
Pt x Ru y Mo z T u formula 1
where T is at least one selected from the group consisting of W, Ni, Sn, Hf 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. %,
wherein the catalyst shows a peak derived from an oxygen bond of T and a peak derived from a metal bond of T in a spectrum measured by an X-ray photoelectron spectral method, and wherein the area of the peak derived from the oxygen bond of T is 80% or less of the area of the peak derived from the metal bond of T.
15. A methanol oxidation catalyst comprising:
nanoparticles having a composition represented by the following formula 1:
Pt x Ru y Mo z T u formula 1
where T 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. %, a part of the Pt and Ru is substituted with at least one selected from the group consisting of Rh, Os, Ir, Pd, Ag and Au,
wherein the area of the peak derived from an oxygen bond of T is 80% or less of the area of the peak derived from a metal bond of T in a spectrum measured by an X-ray photoelectron spectral method.
16. A method for manufacturing the methanol oxidation catalyst according to claim 11 , the method comprising:
keeping a conductive support at 400° C. or less; and
depositing structural metal elements to the conductive support by a sputtering method or vapor deposition method to form the nanoparticles.
17. The method according to claim 16 , further comprising washing the nanoparticles with an acid.
18. The method according to claim 16 , further comprising washing the nanoparticles with an alkali solution.
19. The method according to claim 16 , further comprising subjecting the nanoparticles to a heat treatment.
20. The method according to claim 19 , wherein the heat treatment is carried out in a following condition: temperature of 10° C. or more and 400° C. or less and oxygen partial pressure of less than 5%.
21. The method according to claim 16 , wherein the sputtering method or vapor deposition method allows other materials to deposit on the conductive support.
22. The method according to claim 16 , wherein a dissolvable metal is deposited together with the structural metal elements on the conductive support by the sputtering method or vapor deposition method, the method further comprising washing with an acid to remove the dissolvable metal.