双金属Mo-Ti-SBA-15材料的制备及其环己烯环氧化性能

Synthesis of Bimetallic Catalyst Mo-Ti-SBA-15 and Its Catalysis of Epoxidation Cyclohexene

摘要:

采用一步法分别制备了一系列单金属介孔催化剂Ti-SBA-15-36，Mo-SBA-15-(180/28)和双金属介孔催化剂Mo-Ti-SBA-15-(X)。考察了双金属催化剂Mo-Ti-SBA-15-(X)的Mo含量，对催化剂的结构和催化性能的影响。分析了催化剂活性差异的原因以及探讨了双金属催化剂的催化协同机理。考察了催化环氧化反应中的主要影响因素。结果表明，最佳的双金属催化剂Mo-Ti-SBA-15-(180/28)的催化效果均优于单金属催化剂的环氧化效果。当反应时间为8 h，反应温度为80 ℃，催化剂剂量为25 mg，以环己烯作为底物，TBHP作为氧源，1,2-二氯乙烷作为溶剂时，Ti-SBA-15-36，Mo-SBA-15-(180/28)和Mo-Ti-SBA-15-(180/28)的转化率分别为41.07%、46.44%和98.33%，选择性分别为97.56%、93.19%和98.86%。同时Mo-Ti-SBA-15-(180/28)也具有很好的可循环利用性。

Abstract:

A series of catalysts, including monometallic catalyst Ti-SBA-15-36, Mo-SBA-15-(180/28) and bimetallic catalyst Mo-Ti-SBA-15-(X), were synthesized by the one-step method. The influence of Mo content in the bimetallic Mo-Ti-SBA-15-(X) on catalyst structure and catalytic property was investigated. The reasons for the differences’ catalytic activity in the epoxidation cyclohexene and their synergy mechanism were analyzed. The reaction conditions in the epoxidation cyclohexene reaction were studied. The results showed that the optimum bimetallic catalyst Mo-Ti-SBA-15-(180/28) more catalytic activities than the monometallic catalyst Ti-SBA-15-36, Mo-SBA-15-(180/28). When the reaction condition (catalyst amount: 25mg, cyclohexene: 2.5mmol, TBHP: 5mmol, 1,2-DCE: 10mL, reaction temperature: 80oC, reaction time: 8h) was used, the conversion of Ti-SBA-15-36, Mo-SBA-15-(180/28) and Mo-Ti-SBA-15-(180/28) was 41.07%, 46.44%, 98.33%, respectively, and the selectivity was 97.56%, 93.19%, 98.86%, correspondingly. And the catalyst Mo-Ti-SBA-15-(180/28) has a good reusability.