One-step production of adipic acid from cyclohexane over stable oxides (CeO2 & ZrO2) using O2: Enhanced oxidation activity in acidic medium

One-step production of adipic acid from cyclohexane using O2 is a long due process for replacing conventional two-step process involving nitric acid oxidation of KA-oil. This work presents one-step oxidation of cyclohexane into adipic acid using O2 over stable oxides including CeO2 (Redox) and ZrO2 (Non-Redox) in acid medium. The effect of acidic medium and nature of metal oxide catalysts in cyclohexane oxidation have been investigated. While no activity was observed in solvent-free condition, presence of a polar protic solvent promoted significant improvement in oxidation activity.