NOVELTY - Catalyst contains platinum (less than 50 atomic %), vanadium and iron.    USE - For oxidation-reduction reaction of fuel in electrode of fuel cell (all claimed) used in electrical utility power generation facilities, uninterrupted power supply devices, extraterrestrial vehicles, transportation equipments (such as heavy trucks, automobiles and motorcycles), residential power generation systems, mobile communication equipment (such as wireless telephone, 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 electrocatalyst has improved electrocatalytic cathodic activity during reduction of oxygen, and electrocatalytic anodic activity during oxidation of hydrogen. The electrocatalyst is more active, corrosion resistant and more poison tolerant. Electrocatalyst is used in powder form so as to increase the surface area that increases the number of reactive sites in catalyst. Efficiency of fuel cell using the electrocatalyst is improved.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (a) supported electrocatalyst powder for use in electrochemical reactor devices, comprising catalyst dispersed on electrical conductive support particles;    (b) fuel cell electrode comprising electrode substrate on which electrocatalyst particles containing catalyst is supported;    (c) fuel cell (20) for catalytic oxidation of hydrogen-containing fuel or catalytic reduction of oxygen, comprising anode (22), cathode (23), proton exchange membrane (21) between electrodes, and catalyst;    (d) method for electrochemical conversion of hydrogen-containing fuel and oxygen to reaction products in a fuel cell comprising an electrically conductive external circuit connecting the electrodes, involves contacting fuel or oxygen and catalyst to catalytically oxidize the fuel or catalytically reduce the oxygen; and    (e) unsupported catalyst layer formed on surface of electrolyte membrane or electrode, comprising platinum, vanadium and iron.    DESCRIPTION OF DRAWING(S) - The figure shows the exploded, schematic structural view showing the components of fuel cell.    fuel cell (20)    proton exchange membrane (21)    anode (22)    cathode (23)    current collectors (24,25)    sealants (26,27)    fuel chamber (28)    air chamber (29)