Kinetics, Mechanism, and Activation Energy of H2O2 Decomposition on the Surface of ZrO2

Abstract

The kinetics, mechanism, and activation energy of H2O2 decomposition in ZrO2 particle suspensions were studied. The obtained first-order and second-order rate constants for the decomposition of H2O2 in the presence of ZrO2 at T = 298.15 K produced the values k1 = (6.15 ± 0.04) × 10−5 s−1 and k2 = (2.39 ± 0.09) × 10−10 m·s−1, respectively. The dependency of the reaction first-order rate constant with temperature was studied; consequently, the activation energy for the reaction was obtained in the temperature interval 294.15−353.15 K having yielded the value Ea = 33 ± 1.0 kJ·mol−1. The dependency of the zeroth-order reaction rate constant with pH was investigated and discussed. A mechanistic study encompassing the investigation of the dynamics of formation of hydroxyl radicals during the course of the reaction was performed. A version of the modified Hantzsch method was applied for this purpose, and it was verified that the dynamics of formation of hydroxyl radicals during the reaction are in good agreement...