(US4677092-A)      Ternary metal alloy catalyst contains Co, together with Pt, Ir, Rh, or Pd and a Gp. IV, V, VI, or VII element dispersed on an electrically conductive C powder. The catalyst has an ordered solid soln. and a catalytic activity for the electrochemical redn. of O2 which is at least twice that of unalloyed Pt catalysts on the same powder.    The alloy is pref. Pt, Co, and Cr and the catalytic activity is at least 2 and a half times that of the unalloyed Pt.    USE/ADVANTAGE -   Fuel cell electrode catalyst with good stability and ability to maintain its physical and, chemical integrity after long period of operation.    (US4711829-A)      Fuel cell includes a ternary alloy cathode catalyst consisting of Co together with Pt, Ir, Rh, or Pt and a Gp. IV, Gp.V, Gp.VI, or Gp.VII transition metal.    The catalyst is supported on an electrically conductive C support and has an ordered solid soln. structure. The catalytic activity is at least twice that of an unalloyed Pt catalyst on a similar support. The ternary alloy pref. contains Co, Pt and Cr and the electrolyte in the fuel cell is pref. phosporic acid.    ADVANTAGE -   Stability and specific activity of the catalyst are improved.    (JP95024775-B2)      Fuel cell comprises as cathode catalyst a ternary alloy contg. a noble metal (Pt, Ir, Rh or Pd), Co and a transition metal of gp. IV, V, VI or VII, supported on a carbon conductor, this catalyst having a structure which is an ordered solid soln. The alloy comprises by wt. 6-12% Cr, 8-16% Co, balance Pt, pref. 78% Pt, 14% Co, 8% Cr. The catalyst is prepd. by intimately contacting a finely divided noble metal supported on a conductive carbon support with Co and a transition metal as defined above; heating and reducing these materials in a non-oxidising atmos. to form the catalyst and heating the alloy in an inert atmos. at a rate suitable for forming an ordered solid soln. In the embodiment the main heat treatment is at 815-980 deg.C and the catalyst is cooled to 540-650 deg.C and held for 1 hr. prior to cooling. The supplementary heat treatment is at 600-800 deg.C in H2 for 1-3 hrs. and cooled in non-oxidising atmos.    ADVANTAGE -   The catalyst has a catalytic activity for the electrochemical redn. of O2 at least double that of a non-alloyed Pt catalyst supported on the same conductive carbon support.    (DE3642423-C2)      Fuel cell comprises as cathode catalyst a ternary alloy contg. a noble metal (Pt, Ir, Rh or Pd), Co and a transition metal of gp. IV, V, VI or VII, supported on a carbon conductor, this catalyst having a structure which is an ordered solid soln. The alloy comprises by wt. 6-12% Cr, 8-16% Co, balance Pt, pref. 78% Pt, 14% Co, 8% Cr. The catalyst is prepd. by intimately contacting a finely divided noble metal supported on a conductive carbon support with Co and a transition metal as defined above; heating and reducing these materials in a non-oxidising atmos. to form the catalyst and heating the alloy in an inert atmos. at a rate suitable for forming an ordered solid soln. In the embodiment the main heat treatment is at 815-980 deg.C and the catalyst is cooled to 540-650 deg.C and held for 1 hr. prior to cooling. The supplementary heat treatment is at 600-800 deg.C in H2 for 1-3 hrs. and cooled in non-oxidising atmos.    ADVANTAGE -   The catalyst has a catalytic activity for the electrochemical redn. of O2 at least double that of a non-alloyed Pt catalyst supported on the same conductive carbon support.