Oxygen reduction electrocatalysis enhanced by nanosized cubic vanadium carbide

The cubic vanadium carbides with the size ranging from 5 to 15 nm uniformly dispersed on the carbon matrix have been synthesized by a simple hydrothermal method for the first time. The XRD measurement shows that the cubic vanadium carbide is structured in the form of V8C7. The vanadium carbide cube grows along the {100} planes. The Pt nanoparticles with the average size of 3 nm are uniformly dispersed on both the surfaces of carbon and cubic vanadium carbide (Pt/VC@C) as electrocatalyst for oxygen reduction reaction (ORR). The connection between Pt nanoparticles and the nanosized cubic vanadium carbides favors to enhance the synergistic effect. The mass activity of ORR at 0.9 V versus a reversible hydrogen electrode (RHE) is 230 mA mg(Pt)(-1) on the Pt/VC@C which is 2.4 times larger than that of the benchmark on Pt/C electrocatalyst (97 mA mg(Pt)(-1)). (C) 2011 Elsevier B.V. All rights reserved.