铋改性的钒磷氧化物液相催化氧化环己烷的反应机理

Reaction Mechanism of Liquid-Phase Oxidation of Cyclohexane Catalyzed by Bi-Modified Vanadium-Phosphorous Oxide Catalyst

制备了铋改性的钒磷氧化物(Bi-VPO)催化剂,并将其用于液相催化氧化环己烷,研究了该反应的反应机理.结果表明,铋改性可大大提高VPO催化剂在温和条件下对环己烷液相氧化的催化性能.无溶剂实验和四氢呋喃作溶剂的实验证明反应过程中溶剂乙腈和H2O2之间存在相互作用;自由基捕捉实验证明环己烷氧化过程中存在自由基反应历程;环己醇氧化实验证明环己酮并不是来自环己醇的氧化,而是由环己烷直接氧化得到的.

Bi modified vanadium-phosphorous oxide （Bi-VPO） catalysts were prepared and used in llquid-phase oxidation of eyelohexane. The results showed that Bi modification could greatly enhance the catalytic performance of Bi-VPO for the oxidation of cyclohexane under mild conditions. The experiments without any solvent and with tetrahydrofuran as a solvent indicated the existence of interaction between acetonitrile and hydrogen peroxide. The free radical trap experiment proved that a free radical process is present in the catalytic system. The oxidation experiment of cyclohexanol explained that cyclohexanone is derived directly from cyclohexane oxidation instead of cyclohexanol oxidation.