Selective oxidative conversion of cyclohexylamine to cyclohexanone oxime using an efficient Co-WO3 catalyst: Experimental and theoretical investigations

Abstract

In this contribution, the successful development of an efficient and green approach for producing cyclohexanone oxime (CHO) through highly selective solvent-free oxidative conversion of cyclohexylamine using rGO-based modified WO3 is reported. The role of rGO was emphasized because the presence of hydroxyl groups upon the surface of this species was revealed liable in the absorption and activation process of cyclohexylamine. Under optimum conditions, a total conversion of 81% with selectivity towards CHO of 86% was obtained. Moreover, the results of Density Functional Theory (DFT) confirms the experimental finding of the synergism between Co and rGO components, through their d and P states, on the reactivity of both cyclohexylamine and molecular oxygen. It was shown that the Co atom has a repulsive effect on the reactivity of cyclohexylamine while being attractive for the O2 molecule at the beginning of the reaction.