One-step Synthesis of ε-Caprolactam from Cyclohexane Catalyzed by VPO Composites

A series of transition metal-doped VPO composite catalysts were prepared by impregnating method in an organic medium,and were employed to catalyze reaction of cyclohexane with nitrosyl sulfuric acid in the presence of fuming sulphuric acid.The results show that e-caprolactam can directly be obtained from such one-step catalytic process and the Mn-Al-VPO catalyst works the best with 20.19% of conversion and 48.86% of selectivity to e-caprolactam among these VPO composites,which promises a potential new one-step process for making e-caprolactam from cyclohexane.