Ternary platinum alloy catalyst
A platinum alloy catalyst PtXY, wherein X is nickel, cobalt, chromium, copper, titanium or manganese and Y is tantalum or niobium, characterised in that in the alloy the atomic percentage of platinum is 46-75 at %, of X is 1-49 at % and of Y is 1-35 at %; provided that the alloy is not 66 at % Pt20 at % Cr14 at % Ta or 50 at % Pt, 25 at % Co, 25 at % Ta is disclosed. The catalyst has particular use as an oxygen reduction catalyst in fuel cells, and in particular in phosphoric acid fuel cells.
1. A ternary platinum alloy catalyst PtXY, wherein X is nickel and Y is tantalum, and wherein in the alloy the atomic percentage of platinum is 46-75 at %, of X is 25-40 at % and of Y is 1-20 at %.
2. The ternary platinum alloy catalyst according to claim 1 , wherein the catalyst is unsupported or supported on a dispersed support material.
3. The ternary platinum alloy catalyst according to claim 2 , wherein the catalyst is supported on a dispersed support material.
4. The ternary platinum alloy catalyst according to claim 3 , wherein the support material is a corrosion resistant carbon.
5. An electrode comprising a catalyst according to claim 1 .
6. The electrode according to claim 5 , wherein the electrode is a cathode.
7. A fuel cell comprising an electrode according to claim 5 .
8. The fuel cell according to claim 7 , wherein the fuel cell is a phosphoric acid fuel cell.
9. A catalyst coated membrane comprising a catalyst according to claim 1 .
10. A fuel cell comprising a catalyst coated membrane according to claim 9 .
11. The fuel cell according to claim 10 , wherein the fuel cell is a proton exchange membrane fuel cell.