加氢组分对铜基催化剂CO2加氢直接合成二甲醚性能的影响

以不同加氢组分对CO2加氢合成二甲醚性能的影响为对象,采用XRD、BET、TEM、TPR和TPD对催化剂性质进行了表征.研究结果表明,Cu/HZSM-5催化剂中添加Zn或Mn均能有效提高催化剂的CO2加氢转化活性;同时添加Zn和Mn的Cu-Zn-Mn/HZSM-5催化剂,CO2加氢合成二甲醚性能最好,CO2转化率18.78%,DME选择性46.22%.其中,Mn存在有利于催化剂加氢活性组分的分散,并增加对CO2的吸附能力;Zn的存在则增强了催化剂对H2的吸附活化能力,Zn和Mn同时存在产生的协同作用使催化剂具有很好的CO2加氢合成二甲醚的活性.

Effect of the hydrogenation components on copper-based catalysts for synthesis of dimethyl ether from CO2 hydrogenation

This study focused on the effect of different hydrogenation components,such as Cu-Zn,Cu-Mn and Cu-Zn-Mn,on the catalytic performance in direct DME synthesis from CO2.CO2 conversion and DME selectivity increased obviously when manganese and zinc were added into Cu/HZSM-5 catalyst.Co-added Cu-Zn-Mn/HZSM-5 catalyst showed the highest CO2 conversion(18.78%) and DME selectivity(46.22%).The physico-chemical characteristics of the catalysts characterized by the means of XRD,BET,TEM,TPR and TPD showed that Mn can improve the dispersion of the hydrogenation components in the catalysts and increase the adsorption of CO2;Zn can increase the reducibility of CuO and the adsorption of H2.This synergic effect of Zn and Mn in Cu-Mn-Zn/HZSM-5 catalyst created more and stronger adsorption sites of H2 and CO2,made a favorable catalytic activity for the direct DME synthesis from CO2 hydrogenation.