摘要
以正硅酸乙酯为硅源,采用溶胶-凝胶法制备草酸二甲酯加氢合成乙二醇的Cu/SiO2催化剂,并考察老化时间对Cu/SiO2催化剂活性与结构的影响。用N2物理吸附、XRD、FT-IR和H2-TPR等技术对Cu/SiO2催化剂性能与结构进行表征。结果表明,溶胶-凝胶法制备的Cu/SiO2催化剂中有层状硅酸铜形成,铜物种均匀分布在载体SiO2上,易被还原,活性较高。合理的老化时间可抑制SiO2对催化剂表面活性位的包覆,提高活性。在200℃、2.0 MPa、氢酯物质的量比60∶1、草酸二甲酯空速1.0 h-1和老化时间1.5 h的条件下,草酸二甲酯转化率达99.51%,乙二醇选择性93.60%。
Cu/SiO2 catalysts for hydrogenation of dimethyl oxalate （ DMO ） to ethylene glycol （EG） were prepared by using sol-gel method and tetraethoxysilane （TEOS） as the silicon source. The effects of aging time on the catalytic activity and structure of Cu/SiO2 catalysts were investigated. The catalysts were characterized by N2 physical adsorption, XRD, FT-IR and H2-TPR. The results showed that Cu/SiO2 catalysts prepared by sol-gel method exhibited higher activity for the hydrogenation of DMO and strong reducibility due to the formation of copper phyllosilicate and the well-dispersed copper particles on SiO2 support. The coating of silica on the active sites of catalyst surface was inhibited by controlling reasonable aging time,which improved the catalytic activity of the catalysts. DMO conversion and the selectivity to EG reached 99.51% and 93.60%, respectively under the condition as follows： reaction temperature 200 ℃, reaction pressure 2.0 MPa, n （ H2 ） ： n （DMO） = 60 ： 1, DMO space velocity 1.0 h - l, Cu/SiO2 catalyst prepared by sol-gel method and aged for 1.5 h.
出处
《工业催化》
CAS
2012年第5期47-51,共5页
Industrial Catalysis
