Selective Oxidation of CO over Bimetal Pt0.5M0.5 (M = Fe, Co, Ni) Catalysts Prepared from Complex Binary Salts

Abstract

Nanopowders of Pt 0.5 M 0.5 (M = Fe, Co, Ni) alloys prepared by decomposition of complex binary salts [Pt(NH 3 ) 5 Cl][Fe(C 2 O 4 ) 3 ]·4H 2 O, [Pt(NH 3 ) 4 ][Co(C 2 O 4 )2(H 2 O) 2 ]·2H 2 O, [Pt(NH 3 ) 4 ][Ni(C 2 O 4 )2(H 2 O) 2 ]·2H 2 O, respectively, were studied in the reaction of selective CO oxidation. The bimetal catalysts were shown more active at low temperature than the Pt nanopowder. The catalyst activities decrease in the series of Pt 0.5 Co 0.5  Pt 0.5 Ni 0.5 > Pt 0.5 Fe 0.5 >>Pt. The observed high activity of bimetal Pt 0.5 M 0.5 catalysts at low temperature and considerable coverage of the Pt surface by adsorbed CO molecules may be accounted for by the activation of CO on the Pt atoms and O 2 on the second metal (Fe, Co, Ni) atoms and by the reaction localization on the Pt-M contacts on the alloy nanoparticle surface. The bimetal systems under study can be used for improving practically important catalysts for selective CO oxidation; they also are applicable for reburning of CO and hydrocarbons, hydrogenation, electrochemical reactions etc. The reported method for preparation of bimetal nanopowders based on the decomposition of complex binary salts is simple, does not need expensive reactants and can be easily adapted for synthesis of supported catalysts containing nanoparticles of metal alloys Pt 0.5 M 0.5 (M = Fe, Co, Ni).