Ce掺杂的蛋壳型CuO/ZnO/SiO_2颗粒催化剂的制备和表征  

Preparation and Characterization of Eggshell-shaped CuO/ZnO/SiO_2 Particulate Catalysts Modified with Ce

作　　者：夏增敏[1] 文利雄[1] 宋继瑞[1] 陈建峰[1] 

机构地区：[1]北京化工大学纳米材料先进制备技术与应用科学教育部重点实验室

出　　处：《过程工程学报》2007年第4期812-816,共5页The Chinese Journal of Process Engineering

基　　金：国家自然科学基金资助项目(编号:20325621;20506001);国家重点基础研究发展规划(973)基金资助项目(编号:2003CB615807);中国石油天然气股份有限公司科学研究与技术开发基金资助项目(编号:06-04D-01-01-02);北京市教委基金资助项目(编号:JD100100403)

摘　　要：用添加表面活性剂的两步沉淀法制备了以蛋壳型纳米空心SiO2为载体的CuO/ZnO催化剂和掺杂Ce的CuO/ZnO催化剂,初步考察了两组催化剂用于一氧化碳加氢合成甲醇的催化性能,并采用TEM,BET,XRD,XPS等方法对催化剂的结构进行了表征.结果表明,以纳米空心SiO2为载体的CuO/ZnO催化剂具有较大的比表面积,活性成分在载体表面分散均匀,粒径在13nm左右.加入掺杂剂Ce能有效提高催化剂的活性和选择性:一方面,Ce可以降低Cu2p3/2和Zn2p3/2的表面结合能,使氧化铜更容易被氢气还原成铜;另一方面,Ce也能增强铜锌之间的相互作用,抑制铜粒子的烧结,改善活性成分的分散.Eggshell-shaped CuO/ZnO/SiO2 and CuO/ZnO/Ce/SiO2 particulate catalysts supported with porous hollow SiO2 nanoparticles were prepared by a two-step precipitation method combined with addition of surfactant. The catalytic performances of the prepared catalysts for methanol synthesis from CO hydrogenation were investigated, and the catalyst structure was characterized by TEM, BET, XRD and XPS techniques. The results showed that the catalysts supported with porous hollow SiO2 nanoparticles had large specific surface areas, and the CuO and ZnO particles with an average size of about 13 nm were well dispersed on the support. The Ce promoter could improve the catalytic activity and the selectivity of methanol significantly, probably by two reasons： （1） Ce could lower the binding energy of Cu 2p3/2 and Zn 2p3/2, thus facilitating the reduction of CuO to Cu by hydrogen, and （2） the presence of Ce might enhance the interaction between Cu and Zn, and hence improved the dispersion of active components by preventing Cu particles from aggregating.

关 键 词：蛋壳型 CuO/ZnO/SiO2颗粒催化剂 甲醇合成 纳米SIO2 CE 

分 类 号：O643[理学—物理化学]