Facile solvothermal synthesis of Pt–Cu nanocatalyst with improved electrocatalytic activity toward methanol oxidation

Abstract

A binary metal nanocatalyst of platinum and copper was synthesized using a facile solvothermal process (polyol method). The synthesized catalyst was characterized using energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The electro­chemical performance of the synthesized carbon supported binary metal cat­alyst, Pt–Cu/С, toward methanol oxidation reaction was checked and then com­pared with the commercial Pt/C (ETEK) catalyst, using cyclic voltammetry and chronoamperometric techniques. The Pt–Cu/C catalyst was found to be cubic in shape with indentations on the particle surface, having platinum to copper atomic composition of 4:1, i.e., (Pt₄Cu). The peak current density for Pt–Cu/C catalyst recorded as 2.3 mA cm^-2 at 0.7 V (vs Ag/AgCl) and 50 mV s^-1, was two times higher than the current density of the commercially available Pt/C catalyst (1.16 mA cm^-2 at 0.76 V). Moreover, the Pt–Cu/C catalyst was found to be more durable than the commercial Pt/C catalyst, as the Pt–Cu/C retained 89 % of its initial current density, while the commercial Pt/C catalyst retained 65 % of its initial current density after 300 potential cycles.