Layered Transition Metal Oxynitride Co3Mo2OxN6-x/C Catalyst for Oxygen Reduction Reaction.

Abstract

Transition metal oxynitrides have now garnered growing interest in our quest for highly efficient alternatives to Pt in direct methanol alkaline fuel cells. Herein, carbon supported Co3Mo2OxN6-x was synthesized via a simple two-step approach wherein the reactants undergo refluxing and heat treatment in NH3. For the as-prepared Co3Mo2OxN6-x catalyst, uniformly dispersed on XC-72, with the particle size averaged at 5 nm, the catalytic activities toward oxygen reduction reaction in alkaline media are related to the commercial Pt/C, such as the comparable onset potential (0.9 V vs RHE), half-wave potential (0.8 V vs RHE), and even higher specific activity (82.7 mA cm-2 at 0.7 V). Significantly, the Co3Mo2OxN6-x catalyst was highly stable in terms of 95% current retention after 12 h chronoamperometry measurement, indicative of favorable prospect for the non-noble cathodic catalyst in alkaline fuel cell.