Hosted by: Mingzhao Liu

Identification of active non-noble metal catalysts for the oxygen reduction reaction remains a critical materials challenge in the development of electrochemical energy storage and conversion technologies. Recently, we have demonstrated that alpha nickel hydroxide supported on graphene oxide (-Ni(OH)2/GO) displays a surprising activity for the oxygen reduction reaction in alkaline media. In comparison to -Ni(OH)2 alone or graphene oxide alone, the -Ni(OH)2/GO material displays a lower onset potential and higher peak current density, suggesting a synergy between the GO support and the -Ni(OH)2 material. In order to gain insight into the mechanistic origin of the synergy between the -Ni(OH)2 particles and the GO support, we present a comprehensive kinetic analysis of the supported and unsupported -Ni(OH)2 catalyst. Electron transfer numbers, kinetic rate constants, and reaction orders determined through rotating disk electrode linear sweep voltammetry provide preliminary evidence for similar elementary steps occurring on supported and unsupported -Ni(OH)2, but modifications in activity arising from differences in the activation energy for adsorption of O2 and of reaction intermediates.