HETEROGENEOUS REDOX CATALYSIS AT HYDRATED OXIDE LAYERS

A theoretical model describing heterogeneous redox catalysis at hydrated oxide electrodes is described. It is proposed that the transformation of the substrate to the product occurs via a Michaelis-Menten mechanism in the hydrated oxide layer. The effect of concentration polarization in the electrolyte is included in the theoretical analysis. Analogies may be drawn between heterogeneous redox catalysis at oxide surfaces and treatments describing material transport and electrochemical kinetics at enzyme electrodes. The theoretical model is applied to previously published data, describing the electro-oxidation of formate at thermally prepared RuO2 electrodes in alkaline solutions.