Oxidation of 3,4-dihydroxybenzoic acid by means of hydrogen peroxide in aqueous goethite slurry.

The oxidation by H2O2 of 3,4-dihydroxybenzoic acid (3,4-DHB) in aqueous/goethite slurry at varying operating conditions (catalyst load, temperature, pH, substrate and hydrogen peroxide starting concentration) is investigated. At adopted catalyst loads the observed kinetic developments are consistent with a non-radicalic oxidation mechanism involving the interaction between hydrogen peroxide and 3,4-DHB acid both adsorbed on the active sites of the catalyst. The temperature dependence of rate parameters for the proposed model is also assessed.