摘要
通过控制制备过程中的洗涤次数,采用沉淀凝胶法制备了一系列不同钠离子含量的Co/SiO2催化材料,并采用X射线衍射、N2吸脱附、X射线能谱衍射、H2-程序升温还原、透射电镜和原子吸收光谱等多种表征手段系统研究了材料中残留钠离子对Co/SiO2材料的结构、分散性、氧化还原性和形貌的影响.结果表明,残留的钠离子使得样品比表面积下降,平均孔径增大,导致Co3O4的颗粒尺寸迅速增大.同时钠离子对Co3O4的还原具有抑制作用,使得样品的还原难度增大.结果导致Co/SiO2催化材料在乳酸酯加氢反应中的活性大大降低,同时造成丙酸乙酯副产物增加,对1,2-丙二醇(1,2-PDO)选择不利.
The effect of residual sodium on the Co3 O4/SiO2 catalysts prepared by precipitation-gel method has been investigated in correlation with the detailed characteristics of active component performance and catalytic perform- ance in the hydrogenolysis of ethyl lactate. Characterization of the catalysts showed that the residual sodium had a negative effect on the chemical-physical properties of the catalysts, such as the BET surface area, the particle size of Co3 04, and the reducibility of Co species. As a consequence, the conversion and selectivity of the catalysts in the hydrogenolysis reaction generally decreased with increasing sodium content.
出处
《分子催化》
EI
CAS
CSCD
北大核心
2013年第1期10-15,共6页
Journal of Molecular Catalysis(China)
基金
国家'十二五'科技支撑计划(2011BAE05B02)
