沉淀剂对CuZnAl催化剂催化CO加氢合成C_(2+)醇性能的影响

Effect of Precipitants on the Performance of CuZnAl Catalyst in CO Hydrogenation to C_(2+)OH

分别以碳酸钠、碳酸氢钠、柠檬酸和草酸作为沉淀剂,采用共沉淀法制备CuZnAl催化剂;通过XRD、H 2-TPR、N 2吸附-脱附和NH 3/CO 2-TPD-MS等手段对CuZnAl催化剂进行表征;并探究了其催化CO加氢合成C 2+醇(C 2+OH)的性能。结果表明,沉淀剂的改变影响催化剂上Cu 0的分散性、CuO的还原性以及催化剂的织构性质和其表面酸、碱性,从而显著影响其催化性能。以碳酸钠为沉淀剂制备的CuZnAl催化剂具有较大的比表面积和孔体积,弱碱量和中强碱量的比例适宜;同时,ZnO微晶的形成促进了CuO的还原,提高了Cu 0的分散性,因而使催化剂表现出最佳的催化性能,CO转化率达21.24%,C 2+OH在醇产物中的占比最高,为18.32%。

Using sodium carbonate,sodium bicarbonate,citric acid and oxalic acid as precipitators,CuZnAl catalyst was prepared by co-precipitation method,and characterized by XRD,H 2-TPR,N 2 adsorption-desorption and NH 3/CO 2-TPD-MS,and the catalytic properties were evaluated by CO hydrogenation to C 2+alcohol(C 2+OH).Results show that precipitator significantly affects the dispersion of Cu 0 species,the reduction of CuO,the textural properties,surface acidity and alkalinity of the catalyst.CuZnAl catalyst prepared with sodium carbonate as precipitator has large specific surface area and pore volume,and the ratio of weak base to medium strong base is suitable.At the same time,the formation of ZnO microcrystalline promotes the reduction of CuO and improves the dispersion of Cu 0,therefore the catalyst showed the best catalytic performance,with CO conversion reaching 21.24%and the proportion of C 2+OH in the alcohol product of 18.32%.