Co-APO-5分子筛催化的环己烷选择氧化:溶剂和改性方法对其催化性能的影响

通过合成改性制备了系列Co-APO-5分子筛催化剂，用于环己烷选择氧化，研究了溶剂和改性方法对其催化性能的影响。结果表明，含有π键的极性溶剂对环己烷选择氧化反应有利，环己烷转化率随着π键极性的增加而提高。引入Si和F降低了Co-APO-5分子筛骨架中四配位钴的含量；引入F后Co-APO-5分子筛的结晶度有所提高，而引入Si则能改善Co物种的氧化和还原性，提升其催化反应活性。同时，Co-APO-5的催化活性与其骨架中四配位Co（Ⅱ）的含量相关，说明骨架Co（Ⅱ）是环己烷选择氧化的催化活性中心。

Selective oxidation of cyclohexane over Co-APO-5:Effects of solvent and modification method on the catalytic performance

A series of Co-APO-5 molecular sieves were prepared and used as the catalysts in the selective oxidation of cyclohexane; the effects of solvent and modification method on the catalytic performance of Co-APO-5 were investigated. The results illustrated that polar solvents containing π-bonds are favorable for the oxidation reaction and the conversion of cyclohexane increases with the increase of solvent polarity. The introduction of Si and F leads to a decrease of the tetrahedral cobalt content in the Co-APO-5 framework. However, introducing F can improve the crystallinity of Co-APO-5, whereas adding Si may promote the oxidation and reduction of cobalt species and then enhance the catalytic activity in oxidation. In general, the activity of Co-APO-5 catalysts is related to the content of tetrahedral cobalt in the framework, suggesting that the framework Co(Ⅱ) is probably the catalytically active species for the oxidation of cyclohexane.