Ternary platinum alloy catalyst

Abstract

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.

What is claimed: 
     
         1 . A ternary platinum alloy catalyst PtXY, wherein Xis cobalt, chromium, copper, titanium or manganese 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 platinum alloy catalyst according to  claim 1 , wherein Xis cobalt, chromium or copper. 
     
     
         3 . The platinum alloy catalyst according to  claim 1 , wherein X is cobalt. 
     
     
         4 . The platinum alloy catalyst according to  claim 1 , wherein X is chromium. 
     
     
         5 . The platinum alloy catalyst according to  claim 1 , wherein X is copper. 
     
     
         6 . The platinum alloy catalyst according to  claim 1 , wherein X is titanium. 
     
     
         7 . The platinum alloy catalyst according to  claim 1 , wherein X is manganese 
     
     
         8 . The platinum alloy catalyst according to  claim 3 , wherein the atomic percentage of platinum is 58 at %, of cobalt is 24 at % and of tantalum is 18 at %. 
     
     
         9 . The platinum alloy catalyst according to  claim 1 , wherein the catalyst is unsupported or supported on a dispersed support material. 
     
     
         10 . The platinum alloy catalyst according to  claim 9 , wherein the catalyst is supported on a dispersed support material. 
     
     
         11 . The platinum alloy catalyst according to  claim 10 , wherein the support material is a corrosion resistant carbon 
     
     
         12 . An electrode comprising a catalyst according to  claim 1 . 
     
     
         13 . The electrode according to  claim 12 , wherein the electrode is a cathode. 
     
     
         14 . A fuel cell comprising an electrode according to  claim 12 . 
     
     
         15 . The fuel cell according to  claim 14 , wherein the fuel cell is a phosphoric acid fuel cell.