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

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.

Automated summary

This study reports the successful development of an efficient and green approach for producing cyclohexanone oxime through a solvent-free oxidative conversion reaction using rGO-based modified WO3 catalyst. The presence of hydroxyl groups on rGO surface was found to play a crucial role in the absorption and activation of cyclohexylamine. Under optimized conditions, a total conversion of 81% with a selectivity towards cyclohexanone oxime of 86% was achieved. Density Functional Theory analysis confirmed the synergistic effect between Co and rGO components in enhancing the reactivity of both cyclohexylamine and molecular oxygen.