Cu-ZnO/HZSM-5催化剂的制备、表征及催化性能

Preparation, Characterization and Catalytic Performance of Cu-ZnO/HZSM-5 Catalyst

采用共沉淀沉积法制备了不同Zn含量的Cu ZnO/HZSM 5双功能催化剂,利用XRD、BET、H2 TPR等手段进行表征,并应用于CO2加氢合成二甲醚的反应中。考察了Zn含量对催化剂前驱体晶相结构以及对焙烧后催化剂的比表面积、平均晶粒大小、还原性能以及催化活性等的影响。研究结果表明,催化剂中w(Zn)=28%时,前驱体中含有较多的绿铜锌矿和单斜绿铜锌矿晶相,焙烧后的催化剂比表面积较大,CuO与ZnO的平均晶粒较小,还原峰温度较低,催化活性较高。

Cu-ZnO/HZSM-5 catalysts with different zinc content used for the hydrogenation of CO_2 to dimethyl ether were prepared by a coprecipitation sedimentation method. Precursors were characterized by XRD, BET, H_2-TPR techniques. Effects of zinc content on the structures of precursors, the specific surface areas of calcinated catalysts, the average crystallite size of CuO and ZnO, the TPR profiles and the catalytic performance were studied. Results show that there are more aurichalcite and rosasite in the precursors when zinc content reaches 28 wt % and the followed calcinated catalyst has the larger surface area, the smaller CuO crystallite size, the lower reduction temperature and the higher catalytic activity.