Layered Transition Metal Oxynitride Co₃Mo₂O_<i>x</i>N_6–<i>x</i>/C Catalyst for Oxygen Reduction Reaction

Abstract

Transition metal\noxynitrides have now garnered growing interest\nin our quest for highly efficient alternatives to Pt in direct methanol\nalkaline fuel cells. Herein, carbon supported Co₃Mo₂O_<i>x</i>N_6–<i>x</i> was synthesized via a simple two-step approach wherein the\nreactants undergo refluxing and heat treatment in NH₃.\nFor the as-prepared Co₃Mo₂O_<i>x</i>N_6–<i>x</i> catalyst, uniformly\ndispersed on XC-72, with the particle size averaged at 5 nm, the catalytic\nactivities toward oxygen reduction reaction in alkaline media are\nrelated to the commercial Pt/C, such as the comparable onset potential\n(0.9 V vs RHE), half-wave potential (0.8 V vs RHE), and even higher\nspecific activity (82.7 mA cm^–2 at 0.7 V). Significantly,\nthe Co₃Mo₂O_<i>x</i>N_6–<i>x</i> catalyst was highly stable in terms\nof 95% current retention after 12 h chronoamperometry measurement,\nindicative of favorable prospect for the non-noble cathodic catalyst\nin alkaline fuel cell.