Kinetic Study of the Oxygen Reduction Reaction on Alpha-Ni(OH)2 and Alpha-Ni(OH)2 Supported on Graphene Oxide

Abstract

Development of active non-noble metal catalysts for the oxygen reduction reaction is critical for a range of electrochemical energy storage and conversion technologies. We have recently discovered that alpha nickel hydroxide supported on graphene oxide (α-Ni(OH)2/GO) displays surprising activity for the oxygen reduction reaction in alkaline media. In comparison to α-Ni(OH)2 alone or graphene oxide alone, α-Ni(OH)2/GO possesses a lower onset potential, lower peak current potential, and higher peak current density, suggesting a synergy between the GO support and the α-Ni(OH)2 particles. To investigate the origin of this synergy, we present a comprehensive kinetic analysis of the supported and unsupported α-Ni(OH)2 catalyst. Rotating disk electrode linear sweep voltammetry furnishes electron transfer numbers, kinetic rate constants, and reaction orders which provide preliminary evidence for similar elementary steps occurring on supported and unsupported α-Ni(OH)2, but modifications in activity arising from differences in the activation energy for adsorption of O2 and of reaction intermediates.