Composition-adjustable PtCoCu alloy nanoparticles for promoting methanol oxidation reaction

Abstract

The accumulation of CO–like intermediates on the catalysts surface severely poisons active sites and, consequently, lowers their catalytic activity toward methanol oxidation reaction (MOR). Previous reports indicated that electrons from Co can transfer to Pt atoms based on the difference in electronegativity, thus facilitating the Pt-based catalysts to split the C—H bonds of methanol molecular and oxidize the intermediates generated during MOR. Comparatively, few works on PtCo-based ternary alloy catalysts for MOR were reported. To this end, here, we report one-step method for the synthesis of PtCoCu alloy catalyst. X–ray photoelectron spectroscopy showed a negative shift of the orbital energy of Pt4f in PtCoCu catalyst, compared to PtCo, PtCu and commercial Pt/XC–72 catalysts. Thus, the prepared PtCoCu not only exhibited a negative shift of 130 mV for CO oxidation in comparison with commercial Pt/XC–72 catalyst but also possessed high electrocatalytic activity for MOR relative to PtCo, PtCu and commercial Pt/XC–72 catalysts. In addition, the adjustment of compositions demonstrated that the proper atomic ratio of Co benefited to boost MOR. Therefore, the current work provides a tactics for the controllable synthesis of ternary alloy catalysts which can also be applied to other electrocatalytic reactions beyond MOR.