Kinetics of Oxidation of Cyclohexane to Cyclohexanone and Cyclohexanol Over CuO–ZnO Catalyst

Abstract

This work describes the oxidation of cyclohexane to cyclohexanone and cyclohexanol using a CuO–ZnO catalyst. It was found that the CuO–ZnO catalyst is more active for the oxidation of cyclohexane using H₂O₂ as an oxidizing agent, and further catalyst was characterized by using XRD, FTIR, and XPS analysis. Various reaction parameters, such as the effect of solvent, reaction time, different oxidizing agents, reaction temperature, H₂O₂ to cyclohexane mole ratio, catalyst loading, and stirring speed, have been studied to analyze the catalytic activity. The optimized catalytic activity obtained an 88.2 % conversion of cyclohexane, 86 % selectivity of cyclohexanone, and 14 % cyclohexanol selectivity. The oxidation of cyclohexane and the determination of the activation energy for the reaction was explored using different kinetic models such as the Eley–Rideal and Langmuir–Hinshelwood–Hougen–Watson models. Langmuir–Hinshelwood–Hougen–Watson competitive associative adsorption mechanism with surface reaction as the rate-limiting step is the best-fitted model.