铈改性的铜硅催化剂催化甘油氢解制备1,2-丙二醇

通过沉淀凝胶法制备了不同铈质量分数的铜铈硅催化剂。采用氢气程序升温还原、氢气程序升温脱附、X射线衍射等手段对催化剂进行表征。在连续流动固定床反应器上考察了铜铈硅催化剂上甘油氢解制备1,2-丙二醇的性能。结果表明:铈的引入使催化剂的还原峰从258℃提前到250℃,催化剂的氢脱附峰温度从129℃降低到100℃左右,并且提高了催化剂的稳定性。以乙醇溶剂代替水,抑制了活性中心Cu0晶粒的长大,获得了95.9%的甘油转化率和96.9%的1,2-丙二醇选择性,催化剂在200h内没有出现失活现象。

CATALYTIC HYDROGENOLYSIS OF GLYCEROL TO 1,2-PROPANEDIOLOVER CERIA-PROMOTED Cu/SiO2 CATALYST

A series of ceria-promoted Cu/SiO2 catalysts were prepared by precipitation-gel method.The physic-chemical properties were characterized by H2 temperature-programmed reduction(H2-TPR),H2 temperature-programmed desorption(H2-TPD) and X-ray diffraction(XRD) methods.Their catalytic performance for glycerol hydrogenolysis to 1,2-propanediol were studied in a fixed-bed continuous flow reactor.The results indicated that ceria improved the stability of Cu/SiO2 catalysts by altering the reduction peak from 258 ℃ to 250 ℃and reducing the H2 desorption peak temperature from 129 ℃ to around 100 ℃.Furthermore,replacing water with ethanol can restrain Cu0 from sintering and promote the performance of Cu/SiO2 catalyst,which could keep its activity in 200 h.The conversion of glycerol and the selectivity of 1,2-propanediol could be up to 95.9% and 96.9% respectively.