PtM M Fe, Co, Ni, Ta, Rh, Pd Binary Systems

Cobalt is used to promote CO oxidation in reformers [284, 285], suggesting PtCo alloys may be useful catalysts for H2 oxidation in the presence of CO. PtCo alloys have been proposed as improved methanol oxidation catalysts [286] because cobalt may assist with CO removal (CO is an intermediate in meflianol electrooxidation) through a mechanism analogous to the PtRu bifunctional mechanism. PtCo alloys have also been studied as improved ORR catalysts [200, 287, 288]. In addition to their improved ORR kinetics, these alloys have been shown to be more tolerant to methanol crossover in direct methanol fuel cells (DMFCs), again possibly through improved CO removal kinetics [289]. However, Stevens et al. [235] observed no impact on CO-stripping with the addition of eobalt to Pt, and explained this as due to surface cobalt dissolving away. 

Tantalum is resistant to corrosion because it forms a passivation layer under all practical conditions. In a study of alloys, it was shown that all of the 

PtPd4 providing the best results. More importantly, improved performance compared to PtRu is demonstrated with 100 ppm or more of CO in the fuel stream. 

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