溶胶-凝胶法制备MoO_3/SiO_2催化草酸二甲酯和苯酚酯交换反应  

Transesterification of Dimethyl Oxalate with Phenol over MoO_3/SiO_2 Catalysts Prepared by Sol-Gel Method

作　　者：余晓鹏 张付宝[2] YU Xiao-peng;ZHANG Fu-bao(Department of Chemical Engineering,Sichuan University of Science ＆ Engineering,Zigong 643000,China;Zhonghao Chenguang Research Institute of Chemical Industry Co Ltd,Zigong 643201,China)

机构地区：[1]四川理工学院化学工程学院,四川自贡643000 [2]中昊晨光化工研究院有限公司,四川自贡643201

出　　处：《分子催化》2018年第4期334-341,共8页Journal of Molecular Catalysis(China)

基　　金：四川理工学院人才引进项目(2013RC04)~~

摘　　要：采用溶胶-凝胶法在碱性条件下制备了一系列MoO_3/SiO_2催化剂用于草酸二甲酯和苯酚酯交换反应,并利用XRD、IR、XPS、NH3-TPD等表征催化剂结构.结果表明:弱酸中心是草酸二甲酯和苯酚酯交换反应的活性中心.当MoO_3负载量为12%(重量百分比),p H为9.1时的MoO_3/SiO_2催化剂具有更高的催化性能,这可能与该催化剂表面Mo物种分散更好和更高的酸量有关.在1.20 g MoO_3/SiO_2催化剂,0.20 mol苯酚,n(草酸二甲酯)/n(苯酚)=2,180℃反应3 h的条件下,苯酚转化率达70.0%,甲基苯基草酸酯和草酸二苯酯选择性分别为88.4%和11.5%.A series of MoO3/SiO2 catalysts for the transesterification of dimethyl oxalate （DMO） with phenol were prepared by sol-gel method under alkaline conditions, and their structures were characterized by XRD, FT-IR, XPS and NH3-TPD. The results indicated that weak Lewis acid sites were occurred. When the loading of MoO3 is 12%, the MoO3/SiO2 catalyst prepared at pH = 9.1 exhibited higher catalytic performance, which might be attribu- ted to the higher dispersion of Mo species and the higher surface acid amounts. Under optimal transesterification reaction conditions （ m （catalyst） = 1.20 g, 0.20 mol Phenol, n（DMO）/n（Phenol）= 2, T= 180 ℃, t = 3 h）, the conversion of phenol reached 70.0%, and the selectivities to methyl phenyl oxalate （MPO） and diphenyl oxalate （DPO） were 88.4% and 11.5%, respectively.

关 键 词：溶胶-凝胶法 MoO3/SiO2催化剂 甲基苯基草酸酯 草酸二苯酯 酯交换 

分 类 号：O643.36[理学—物理化学]