Ionic Liquid-Modified Co/ZSM-5 Catalyzed the Aerobic Oxidation of Cyclohexane: Toward Improving the Activity and Selectivity
Ionic Liquid-Modified Co/ZSM-5 Catalyzed the Aerobic Oxidation of Cyclohexane: Toward Improving the Activity and Selectivity
复制标题
离子液体修饰Co/ZSM-5催化环己烷有氧氧化：提高活性和选择性
DOI：
10.1021/acs.iecr.9b04100
复制
发表时间：
2019-10-30
影响因子：
4.2
通讯作者：
Shao, Zongping
中科院分区：
文献类型：
--
作者：
Hong, Yun;Fang, Yanxion;Shao, Zongping
离子液体（IL）改性的金属/ZSM-5复合材料作为非均相催化剂对环己烷有氧氧化，表现出优异的KA油（环己醇和环己酮）的选择性与改善的活性。进一步系统地研究了IL的不同官能团对氧化的影响。催化剂的催化活性与离子液体的阴离子基团密切相关，而阳离子基团的影响不明显。在优化的催化剂C6 mimHSO 4-Co/ZSM-5上，环己烷转化率和KA油选择性分别达到9.7%和92.2%。这种良好的催化性能主要归因于IL的阴离子基团对环己烷的活化，而优异的选择性归因于KA油在IL中的上级溶解性，同时避免了过氧化。基于原位电子顺磁共振谱的结果，还提出了涉及自由基过程的催化机理。
Ionic liquid (IL)-modified metal/ZSM-5 composites served as heterogeneous catalysts toward cyclohexane aerobic oxidation, demonstrating excellent KA oil (cyclohexanol and cyclohexanone) selectivity with improved activity. The effects of the different functional groups of the IL on the oxidation were further systematically investigated. The catalytic activity of the catalyst was closely related to the anionic group of the IL, whereas the cationic group had no obvious effects. The cyclohexane conversion and selectivity of KA oil reached 9.7 and 92.2%, respectively, using the optimized catalyst C6mimHSO4-Co/ZSM-5. This favorable catalytic performance was mainly attributed to the activation of the cyclohexane by the anionic group of the IL, whereas the excellent selectivity was ascribed to the superior solubility of KA oil in the IL while avoiding overoxidation. Based on the results of in situ electron paramagnetic resonance spectra, a catalytic mechanism involving a free-radical process was also proposed.