Electrochemical Oxidation of Nitrite on a Rotating Gold Disk Electrode: A Second-Order Homogeneous Disproportionation Process

The rate of the homogeneous decomposition of nitrogen dioxide, k, In acid media hasbeen determined from an analysis of the values of the diffusion controlled limiting currentsfor the oxidation of nitrite on a rotating Au disk electrode. The methodology used Is based on the theory of second-order homogeneous disproportionation processes and yielded a value for k of (1.9 ± 0.5) X 10° cm³.mol^-1-s^-1, which compares favorably with that reported earlierIn the literature. The introduction of an approximate form for the currents below their diffusion limiting values made It possible to obtain rather accurate analytical expressions that relate E_1/2 with the rotation rate and the bulk concentration of the reactant, providing an expedient diagnostic criterion for the Identification of second-order homogeneous disproportionation processes.