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以柠檬酸为燃烧剂,采用固态研磨-燃烧法和机械混合法制备了CuO-ZnO-ZrO2/HZSM-5CO2加氢一步合成二甲醚双功能催化剂.采用固定床反应器,在反应温度270℃、压力为3.0 MPa、空速4 200 h-1条件下,考察了催化剂对CO2加氢一步合成二甲醚的反应性能,并采用XRD、BET、H2-TPR、NH3-TPD及XPS对催化剂的结构进行了表征.评价结果表明:随柠檬酸量的增加,二甲醚选择性和收率呈峰形变化趋势;当柠檬酸的量等于化学计量比的100%时,制备的催化剂具有较好的催化性能:CO2单程转化率为24.8%、二甲醚(DME)的选择性和收率分别为35.3%和8.7%.表征结果表明:柠檬酸的量影响催化剂的比表面积、还原性能以及CuO和ZnO的晶粒尺寸等,进而影响催化剂反应性能.
The bimetallic catalyst with hydrogenation of CuO-ZnO-ZrO2 / HZSM-5CO2 was synthesized by the solid state grinding-combustion method and mechanical mixing method using citric acid as the combustion agent.The fixed bed reactor was used at the reaction temperature of 270 ℃ , The pressure of 3.0 MPa, the space velocity of 4 200 h-1 under the conditions of the catalyst on the CO2 hydrogenation of one-step synthesis of dimethyl ether reaction performance and the use of XRD, BET, H2-TPR, NH3-TPD and XPS catalyst The results showed that with the increase of citric acid, the selectivity and yield of dimethyl ether showed a peak-shaped trend. When the amount of citric acid was equal to 100% of the stoichiometric ratio, the prepared catalyst had better performance The conversion of CO2 was 24.8%, the selectivity and yield of dimethyl ether (DME) were 35.3% and 8.7% respectively.The characterization results showed that the amount of citric acid affected the specific surface area, the reduction performance of CuO And the grain size of ZnO, which in turn affect the catalyst reactivity.