Electrocatalysis of oxygen reduction on carbon-supported PtCo catalysts prepared by water-in-oil micro-emulsion

Synthesis of carbon-supported PtCo/C using micro-emulsion method including simultaneous procedure and sequential procedures in both acid and alkaline media was reported. UV-vis and electron microscopy were used to characterize the formation, surface morphology and distribution of PtCo nanoparticles. Crystallite structure of catalysts was analyzed from XRD patterns. Catalytic properties of PtCo/C catalysts synthesized were compared with commercial Pt/C using RDE based on both mass activity (MA) and specific activity (SA). PtCo/C catalysts prepared in both acidic and basic conditions showed better performance than commercial Pt/C catalyst. High-temperature heat treatment was found useful only to PtCo/C by sequential procedure. The peroxide yield was also explored using RRDE technique. The H₂O₂ yield results were correlated with SA and R values (ratio of charge transferred about Co and Pt on the surface of catalyst) obtained from CVs in 1 M KOH solution. A sacrificial Co oxidized effect on impediment of adsorption of OH may cause higher catalytic properties and higher H₂O₂ yield to Pt base alloy catalysts.