四氯乙烷催化脱氢生产四氯乙烯催化剂研究——沉淀剂浓度对催化剂性能的影响

以氢氧化钠为沉淀剂,制备系列Cu-Zn-Ca-Zr-O复合氧化物催化剂,考察沉淀剂浓度对催化剂形貌及催化性能的影响,通过XRD、SEM、TEM、TPR、BET和XPS等对催化剂进行表征。结果表明,沉淀剂浓度对催化剂形貌和孔径均有影响,制备的催化剂中,分散在载体表面的氧化铜起主要催化作用,是催化活性中心。考察催化剂对四氯乙烷脱氢制备四氯乙烯反应的催化性能,结果表明,在反应温度310℃、空速0.5 h-1和沉淀剂质量浓度10%条件下,催化剂催化四氯乙烷脱氢的活性最高,四氯乙烷转化率为80.0%,四氯乙烯选择性为96.0%。

Study of the catalysts for dehydrogenation of tetrachloroethane to tetrachloroethylene:effects of precipitator concentrations on catalyst performance

Using sodium hydroxide with different concentrations as the precipitator,a series of Cu-Zn-Ca-Zr-O mixed oxide catalysts was prepared by co precipitation method.The as prepared catalysts were characterized by XRD,SEM,TEM,TPR,BET and XPS.The influence of precipitator concentrations on the morphology and the performance of the catalysts was investigated.The results showed that precipitator concentration controlled the pore structure and specific surface area of catalysts.The high dispersed copper oxide on support surface contributed primarily to the reaction activity and was the catalytic active centre.The catalytic properties of Cu-Zn-Ca-Zr-O catalysts were investigated by dehydrogenation of tetrachloroethane to tetrachloroethylene.The results indicated that the catalyst prepared with the precipitator NaOH of 10wt% exhibited the highest catalytic activity under the optimal condition of reaction temperature 310 ℃and space velocity 0.5 h^-1.The conversion of tetrachloroethaneand the selectivity to tetrachloroethylene was 80.0% and 96.0%,respectively.