席夫碱Mo(VI)功能化介孔SiO2的制备及其催化烯烃环氧化研究  

Preparation of Mo(VI) Schiff Base Functionalization Mesoporous SiO_2 and Catalytic Olefin Epoxidation

作　　者：张建 赵苑 李昂[1] 丁佳佳 张刚 李洵洲 

机构地区：[1]兰州城市学院化学与环境工程学院.甘肃兰州730070 [2]上海赢创食品有限公司.上海201806

出　　处：《分子催化》2018年第1期70-78,共9页Journal of Molecular Catalysis(China)

基　　金：国家自然科学基金(项目批准号：31560185),兰州城市学院青年教师科研资助项目(LZCU-QN2017-19),浙江省公益技术应用研究项目(2016C32011)

摘　　要：采用共缩聚法制备有机-无机杂化材料,以介孔SiO_2材料为载体,分别嫁接席夫碱配体和配位乙酰丙酮钼,得到Mo(VI)席夫碱修饰的介孔SiO_2(Mo-SB-Cl-SiO_2-0.5-1).所制备的材料采用XRD,SEM,N2吸附-脱附和TEM技术对其结构进行了表征.考察了Mo-SB-Cl-SiO_2-0.5-1催化液相烯烃环氧化性能,结果表明:Mo-SB-Cl-SiO_2-0.5-1催化剂对烯烃环氧化具有高的转化率和优良的催化活性.与后嫁接法制备的催化剂相比,Mo-SB-Cl-SiO_2-0.5-1催化剂催化活性得到明显提高,催化环己烯环氧化的转化率和选择性分别为85%和>99%.在不同烯烃的研究中,环辛烯具有最高的转化率和选择性,分别为87%和>99%.催化剂重复使用4次后,环己烯的转化率没有明显下降,选择性仍然高达98%,表明Mo-SB-Cl-SiO_2-0.5-1具有较好的催化稳定性.The co-condensation strategy was proposed to be adopted to prepare the organic/inorganic hybrid materials. In this preparation, mesoporous SiO2 acted as the support. After grafting the Schiff base ligand and coordinating molybdenum acetylacetonate, the Mo （VI） Schiff base was modified mesoporous SiO2 （Mo-SB-Cl-SiO2-0.5-1） then formed under the condition of co-condensation. The XRD, SEM and N2 adsorption-desorption and TEM techniques were applied to characterize the structure of materials. The catalytic performance of Mo-SB-Cl-SiO2-0.5-1 was discussed in liquid olefins epoxidation system. The results showed a higher conversion and excellent catalysis activity in epoxidation of olefins. In comparison with that catalyst prepared by post-grafting method, the Mo-SB-Cl-SiO2-0.5-1 catalyst showed an enhanced epoxidation activity and selectivity. In the reaction of cyclohexene, the conversion and selectivity were 85% and 〉99%, respectively. For the study on influences of different olefins, the highest conversion （87%） and selectivity （〉99%） were found for cyclooctene had over Mo-SB-Cl-SiO2-0.5-1. After being reused for 4 times, the conversion of cyclohexene hardly declined and the selectivity was still high to be 98%, which indicated that the good reusability of Mo-SB-Cl-SiO2-0.5-1.

关 键 词：共缩聚 有机.无机杂化 催化 烯烃 液相环氧化 

分 类 号：TQ203.2[化学工程—有机化工] O643.3[理学—物理化学]