CO_2加氢合成二甲醚催化剂双组份复合方法研究

采用悬浮并流、湿混和干混的方法制备CuO-ZnO-Al2O3/HZSM-5双功能催化剂。考察了不同混合方法对催化剂催化性能的影响。结果表明,采用悬浮液并流共沉淀法制备的双功能催化剂,对CO2加氢直接合成二甲醚有较高的催化性能:在固定床反应器中,当温度为270℃,压力为3.0MPa,空速为4800h-1时,CO2的单程转化率达到27.12%,二甲醚的选择性达到47.63%。采用BET、XRD、TPR、TPD等对催化剂结构进行表征,结果表明HZSM-5分子筛的加入促进了CuO组分的分散,增加了催化剂整体的比表面积;同时CuO-ZnO-Al2O3组分也在一定程度上改变了HZSM-5的酸性中心的强度以及数量。

Mixing methods of the bifunctional catalyst for dimethyl ether synthesis from CO_2 hydrogenation

The bifunctional catalysts of CuO-ZnO-Al2O3/HZSM-5 for dimethyl ether synthesis from CO2 hydrogenation were prepared by suspended parallel-flow-coprecipitation,dry mixing and wet mixing methods,respectively.Effects of the preparation methods on the catalytic performance were investigated.The results showed that the coprecipitated catalyst had optimum activity,and at 270℃,3.0MPa and space velocity of 4800h-1,the one-through conversion of CO2 could reach 27.12% with the selectivity to dimethyl ether of 47.63%.The BET,XRD,TPR and TPD characterization results indicated that the introduction of HZSM-5 zeolite improved the dispersion of CuO and the specific surface area of the catalysts.Compared to pure HZSM-5,the intensity and quantity of the acidic center of the bifunctional catalysts were modified,which improved the catalytic performance of the catalysts.