Catalytic supercritical water oxidation of 1,4-dichlorobenzene

Abstract

Catalytic supercritical water oxidation occurs through a combination of reaction pathways, consisting of heterogeneous oxidation on the surface of the catalyst and homogeneous oxidation in the solvent. The overall reaction rate should be a combination of the rates of the individual pathways and thus greater than either catalytic oxidation or supercritical water oxidation. Experiments, however, indicate that the reaction rate is slower during catalytic oxidation in supercritical water than during gas-phase catalysis. Continuous flow experiments in supercritical water indicate that both the adsorption equilibrium constant and the rate constant for adsorption are enhanced at high pressure. Thus, the mechanism for catalytic inhibition by supercritical water appears to be a shift in the equilibrium of the adsorbed reactant, and therefore a change in the rate determining step of the catalytic reaction.