Porous core-shell platinum-silver nanocatalyst for the electrooxidation of methanol

A new class of platinum-silver nanomaterial for the catalytic electrooxidation of methanol is considered here. The material was synthesised on a carbon nanochips platform via a combination of chemical reduction to form a particulate bimetallic alloy (Pt₂Ag₁/f-CNC) and an anodic-etching process to form a unique porous core-shell platinum-silver nanoparticle (np-Pt₂Ag₁/f-CNC). Morphology, structural and compositional characterisations of the alloy were performed using transmission electron microscopy (TEM), energy-dispersive X-ray spectrometry (EDX), thermogravimetric analysis (TGA) and X-ray diffraction (XRD) techniques. Data confirms average particle size of 2.07nm (median 1.73nm). The alloy nature of the nanoparticle was confirmed by XRD and TEM/EDX analysis. The np-Pt₂Ag₁/f-CNC material was examined in electrochemical studies as a catalyst for the oxidation of methanol in sulfuric acid electrolyte. Catalytic efficiency is reported in terms of oxidation current density, 134.8mAmg^-1 (platinum mass) and a current ratio, I_f/I_b=0.86. The electrochemical data is indicative of high catalytic rates for methanol conversion, as well as the effectiveness of porous core-shell platinum-silver particles to resist carbon monoxide poisoning. The work demonstrates improved long-term catalytic performance of a novel nanomaterial electrode offering promising energy applications.