Noble metal-based electrocatalyst and method of treating a noble metal-based electrocatalyst

Patent metadata

Field	Value
Publication number	US-9680161-B2
Application number	US-201414331697-A
Country	US
Kind code	B2
Filing date	Jul 15, 2014
Priority date	Jul 15, 2013
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

A noble metal-based electrocatalyst comprises a bimetallic particle comprising a noble metal and a non-noble metal and having a polyhedral shape. The bimetallic particle comprises a surface-segregated composition where an atomic ratio of the noble metal to the non-noble metal is higher in a surface region and in a core region than in a sub-surface region between the surface and core regions. A method of treating a noble metal-based electrocatalyst comprises annealing a bimetallic particle comprising a noble metal and a non-noble metal and having a polyhedral shape at a temperature in the range of from about 100° C. to about 1100° C.

First claim

The invention claimed is:

1. A noble metal-based electrocatalyst comprising:
a bimetallic particle comprising a noble metal and a non-noble metal and having a polyhedral shape, the bimetallic particle comprising a surface-segregated composition where an atomic ratio of the noble metal to the non-noble metal is higher in a surface region and in a core region than in a sub-surface region between the surface and core regions,
wherein the core region has a size of from about 40% to about 60% of a size of the bimetallic particle, wherein the surface region has a thickness of from about 10% to about 30% of the size of the bimetallic particle, and wherein the sub-surface region has a thickness of from about 10% to about 50% of the size of the bimetallic particle.

2. The noble metal-based electrocatalyst of claim 1 further comprising a plurality of the bimetallic particles.

3. The noble metal-based electrocatalyst of claim 2 , wherein the bimetallic particles are agglomerated.

4. The noble metal-based electrocatalyst of claim 2 , wherein the bimetallic particles are non-agglomerated.

5. The noble metal-based electrocatalyst of claim 2 , further comprising a support underlying the bimetallic particles, the bimetallic particles being dispersed on the support.

6. The noble metal-based electrocatalyst of claim 1 , wherein the bimetallic particle has a size of at least about 10 nm.

7. The noble metal-based electrocatalyst of claim 1 , wherein the polyhedral shape is selected from the group consisting of: cube, truncated octahedron, octahedron, truncated tetrahedron, tetrahedron, and icosahedron.

8. The noble metal-based electrocatalyst of claim 1 , wherein the noble metal is selected from the group consisting of: Pt, Pd, Au, Ag, Ru, Rh, Os, and Ir, and wherein the non-noble metal is selected from the group consisting of: Ti, V, Cr, Mn, Mo, Zr, Nb, Ta, Zn, In, Sn, Sb, Pb, W, Co, Cu, Ni and Fe.

9. The noble metal-based electrocatalyst of claim 8 , wherein the noble metal comprises Pt and the non-noble metal comprises Ni.

10. The noble metal-based electrocatalyst of claim 1 , wherein an atomic ratio of the noble metal to the non-noble metal in the surface region and in the core region is from 0.5 to about 4.

11. The noble metal-based electrocatalyst of claim 1 , wherein the atomic ratio of the noble metal to the non-noble metal in the sub-surface region is from about 0.2 to about 3.

12. The noble metal-based electrocatalyst of claim 1 , wherein the polyhedral shape comprises {111} facets.

Assignees

• Univ Illinois

Inventors

• Yang Hong
• Wu Jianbo

Classifications

• B22F1/142

  Thermal or thermo-mechanical treatment · CPC title

• B22F1/145

  Chemical treatment, e.g. passivation or decarburisation · CPC title

• B22F1/0553

  Complex form nanoparticles, e.g. prism, pyramid, octahedron · CPC title

• H01M4/921 Primary

  Alloys or mixtures with metallic elements · CPC title

• H01M4/926 Primary

  on carbon or graphite · CPC title