NOVELTY - A catalyst for use in oxidation or reduction reactions comprises platinum, indium, and at least one of tungsten, iron, and manganese.    USE - The invention is used in oxidation or reduction reactions. It is used for electrocatalyst particles for a fuel cell electrode of a fuel cell (claimed) such as polyelectrolyte membrane fuel cell. Fuel cells are used in electrical utility power generation facilities; uninterrupted power supply devices; extraterrestrial vehicles; transportation equipment such as heavy trucks, automobiles, and motorcycles; residential power generation systems; mobile communications equipment such as wireless telephones, pagers, and satellite phones; mobile electronic devices such as laptop computers, personal data assistants, audio recording and/or playback devices, digital cameras, digital video cameras, and electronic game playing devices, military and aerospace equipment such as global positioning satellite devices; and robots.    ADVANTAGE - The invention provides an electrocatalyst having improvement in corrosion resistance and/or activity.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) a supported electrocatalyst powder for use in electrochemical reactor devices, the supported electrocatalyst powder comprising a catalyst that comprises platinum, indium, and at least one of tungsten, iron, and manganese, and electrically conductive support particles upon which the catalyst is dispersed;    (2) a fuel cell comprising an anode, a cathode, a proton exchange membrane between the anode and the cathode, and a catalyst that comprises platinum, indium, and at least one of tungsten, iron, and manganese for the catalytic oxidation of a hydrogen-containing fuel or the catalytic reduction of oxygen; and    (3) a method for the electrochemical conversion of a hydrogen-containing fuel and oxygen to reaction products and electricity in a fuel cell, comprising contacting the hydrogen-containing fuel or the oxygen and the catalyst to catalytically oxidize the hydrogen-containing fuel or catalytically reduce the oxygen.    DESCRIPTION OF DRAWING(S) - The figure shows a photograph of a TEM image of a carbon support with alloy nanoparticles.