Zr促进的Cu-ZnO/HZSM-5合成二甲醚催化剂的制备

PREPARATION OF ZIRCONIA PROMOTED Cu-ZnO/HZSM-5 CATALYST FOR DIMETHYL ETHER SYNTHESIS

采用共沉淀沉积法制备了Cu-ZnO-ZrO2／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。考察了沉淀剂、硝酸盐浓度、共沉淀温度、pH值、焙烧温度等对催化性能的影响。研究结果表明,以Na2CO3作为沉淀剂,在硝酸盐浓度0.2 mol／L、沉淀温度80℃、pH值9.0、焙烧温度300℃的条件下,Cu-ZnO-ZrO2／HZSM-5双功能催化剂具有最佳的催化活性。ZrO2的作用主要表现为促进CuO和ZnO的分散,降低还原温度以及抑制逆水气变换副反应等。

Zirconia promoted Cu-ZnO/HZSM-5 catalysts for the synthesis of dimethyl ether from carbon dioxide hydrogenation were prepared by a coprecipitation sedimentation method. The catalysts were characterized by XRD, BET and H2-TPR techniques. Effects of precipitants, nitrate concentration, coprecipitation temperature, pH value, and calcination temperature on catalytic activity were studied. The best catalytic activity was achieved under the preparation conditions of using sodium carbonate as precipitant, nitrate concentration 0. 2mol/L, coprecipitation temperature 80℃ , pH 9. 0 and calcination temperature 300 ℃. The added zirconia promoted the dispersion of copper oxide and zinc oxide, decreased the reduction temperature and suppressed the reverse water gas shift (RWGS) reaction.