催化学报

催化学报 ›› 2006, Vol. 27 ›› Issue (10): 927-931.

• 研究论文 • 上一篇    下一篇

助剂SiO2对CO2加氢制二甲醚催化剂Cu-ZnO/HZSM-5性能的影响

王继元,曾崇余,吴昌子   

  1. 南京工业大学化学化工学院, 江苏南京 210009
  • 收稿日期:2006-10-25 出版日期:2006-10-25 发布日期:2010-11-28

Effect of Silica Promoter on Properties of Cu-ZnO/HZSM-5 Catalyst for CO2 Hydrogenation to Dimethyl Ether

WANG Jiyuan, ZENG Chongyu*, WU Changzi   

  1. College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009, Jiangsu, China
  • Received:2006-10-25 Online:2006-10-25 Published:2010-11-28

PDF

774

被引次数

47

摘要： 考察了助剂SiO2对CO2加氢合成二甲醚催化剂Cu-ZnO/HZSM-5性能的影响,并用X射线衍射、程序升温还原和X射线光电子能谱等手段对催化剂进行了表征. 结果表明,加入少量的SiO2即可显著提高CO2的转化率、二甲醚的选择性以及二甲醚和甲醇的总选择性,并降低副产物CO的选择性,同时改善催化剂的稳定性; 但SiO2加入量大时,催化活性反而降低. SiO2的存在可使焙烧后催化剂的晶型结构发生改变,促进CuO和ZnO的分散,并提高CuO的还原温度. SiO2的加入抑制了反应过程中催化剂上Cu0和ZnO晶粒的长大,对活性物种Cu0有稳定作用,从而有利于提高催化剂的活性和稳定性.

关键词: 二氧化硅, 铜基催化剂, 二氧化碳, 催化加氢, 二甲醚

Abstract: The effects of the silica promoter on the properties of the Cu-ZnO/HZSM-5 catalyst were investigated by means of X-ray diffraction, temperature-programmed reduction, and X-ray photoelectron spectroscopy. The addition of a small amount of silica (e.g. 1.0%) to Cu-ZnO/HZSM-5 could greatly improve the CO2 conversion and the selectivity for dimethyl ether, and decrease the selectivity for CO, and increase the catalytic stability of the catalyst. However, a large amount of silica caused a decrease in the catalytic activity. The presence of SiO2 led to the changes of phase structure in calcined samples, improved the dispersion of CuO and ZnO, and increased the reduction temperature of CuO. The silica added could suppress the crystallization of Cu0 and ZnO during the reaction, stabilize the active Cu0, and thus improve the activity and stability of the catalyst.

Key words: silica, copper-based catalyst, carbon dioxide, catalytic hydrogenation, dimethyl ether