WO_3/ZrO_2-Cu/ZnO催化剂催化甘油氢解性能

Catalytic performance of Cu/ZnO-WO_3/ZrO_2 catalysts for hydrogenolysis of glycerol

采用共沉淀法制备Cu/ZnO催化剂,浸渍焙烧法制备WO3/ZrO2催化剂,将2种催化剂进行物理混合制得Cu/ZnO-WO3/ZrO2混合催化剂。通过H2程序升温还原(H2-TPR)、H2程序升温脱附(H2-TPD)等手段对催化剂的物化性质进行表征,在连续流动固定床反应器中考察Cu/ZnO-WO3/ZrO2催化剂对甘油氢解反应的催化性能。结果表明:添加WO3/ZrO2可改善催化剂的还原性能和氢吸附性能,催化剂的稳定性明显提高。在反应温度190℃、H2压力3 MPa、80%甘油水溶液、甘油质量空速0.6 h-1的反应条件下,3Cu/ZnO-WO3/ZrO2催化剂上能获得77.6%的甘油转化率和95.8%的1,2-丙二醇选择性,且反应200 h内,催化剂的催化性能基本无变化。

The Cu/ZnO catalyst was prepared by a co-precipitation method and the WO3/ZrO： catalyst was prepared by a impregnation calcination method. The Cu/ZnO-WO3/ZrO2catalyst was composed of a physical mixture of Cu/ZnO and WOJZrO2. The physic-chemical properties of the catalysts were charac- terized by H2 temperature programmed reduction （H2-TPR） and H2 temperature programmed desorption （ H2-TPD）. The performances of the catalysts for glycerol hydrogenolysis to 1,2-propanediol were inversti- gated in a continuous flow fixed-bed reactor. Results showed that the reduction performances and hydrogen adsorption properties of the catalysts with addition of WO3/ZrO2 were improved. Owing to the presence of WOJZr02 ,the stability of Cu-ZnO catalysts was markedly enhanced. Under the conditions of 190℃ ,3 MPa,80% glycerol solution and weight hourly space velocity 0.6 h-1 ,the conversion of glycerol over 3Cu/ZnO-WO3/ZrO2 was 77.6% and the selectivity for 1,2-propanediol was 95.8%. The performances of the catalyst were stable during 200 h operation.