摘要
采用共浸溃法制备了CuCo／SiO2双金属催化剂，以CO加氢合成低碳醇为模型反应考察了不同反应温度、压力和空速下催化剂的反应性能，并采用X射线（XRD）、热重分析（TG）和程序升温还原（TPR）技术对催化剂进行了表征。结果表明，（533～563）K，随反应温度升高，CO转化率从14．9％增加到40．4％，醇类的时空收率呈现先增大再减小的趋势，553K取得最优值；升高反应压力能显著提高醇类的选择性；（1200—4800）h^-1，随空速增加，CO加氢活性降低，醇类产物的选择性显著增加，使时空收率提高。XRD结果表明，反应前催化剂主要成分为CuO、Co3O4和CuCo尖晶石物相，反应后则为Cu^0和Co^2＋。TG和TPR结果表明，前驱体的适宜焙烧温度为623K，催化剂的原位还原温度为593K。
CuCo/SiO2 bimetallic catalyst was prepared by co-impregnation and its catalytic behaviors were investigated using CO hydrogenation to lower alcohols as the model reaction, including the influence of reaction temperature, reaction pressure and space velocity. The catalyst was characterized by XRD, TG and TPR. CO conversion increased from 14.9% to 40.4% while reaction temperature was raised from 533 K to 563 K ; the space timely yield （STY） of alcohols first increased then declined with temperature, with maximum STY at 553 K; the selectivity to lower alcohols significantly increased with pressure. When space velocity was raised from 1 200 h^- 1 to 4 800 h^- 1, CO hydrogenation activity declined while selectivity to and hence STY of lower alcohols increased remarkably. XRD results indicated that main components of the catalyst were CuO, Co304 and Cu-Co spinel before the reaction and Cu^0 and Co^2 ＋ after the reaction. The appropriate calcination temperature of the precursor was determined at 623 K by TG. TPR results showed the optimal in situ reduction temperature was 593 K.
出处
《工业催化》
CAS
2008年第10期105-109,共5页
Industrial Catalysis
基金
国家自然科学基金重大专题项目(205903603)
关键词
有机合成化学
CO加氢
铜钴双金属催化剂
低碳醇
organic synthesis chemistry
CO hydrogenation
copper-cobalt bimetallic catalyst
lower alcohols
