An ion exchange route to produce carbon supported nanoscale vanadium carbide for electrocatalysis

Abstract

We demonstrate that vanadium carbide nanocrystals down to 2 nm on carbon (C-VCx) can be synthesized through a novel route based on an ionic exchange process to locally anchor the species of interest by design. The structures, morphologies and catalytic performance of the as-synthesized nanomaterials were characterized by various physical and electrochemical methods. The results indicate that electrocatalysts made with Pt nanoparticles on C-VCx (Pt/C-VCx) are highly active and stable for both the oxygen reduction reaction (ORR) and methanol oxidation. A mass activity of 267.1 mA mg−1Pt at 0.9 V was obtained for the oxygen reduction reaction, which is much higher than that of a commercial Pt/C electrocatalyst (112.5 mA mg−1Pt). It was also demonstrated that the onset potential for methanol oxidation on Pt/C-VCx is negatively shifted by more than 100 mV compared with that on Pt/C. The origin of these improvements in the catalytic activity can be attributed to the synergistic effect between Pt and VCx. The novelty of the present method is its simplicity and effectiveness, and it can be readily scaled up for mass production of other nanomaterials.