摘要
以H2O2为氧源，乙腈为溶剂，考察了Li掺杂MgO，Li／MgO，对苯乙烯环氧化反应的影响．并用X射线衍射、热重（TG）、扫描电子显微镜（SEM）和CO2程序升温脱附（CO2-TPD）对Li／MgO进行了表征．结果表明，随Li量增加（1％～5％），苯乙烯转化率和环氧化物选择性增加．5％Li／MgO，苯乙烯转化率达99．5％，环氧苯乙烷选择性为95．9％．增加Li量至11％，Li／MgO的活性和选择性基本不变．这主要归于Li／MgO碱的强度和强碱位数目的变化．
The effect of the Li addition to MgO on the styrene epoxidation was studied for H2O2 as an oxidant in the presence of acetonitrile. The physicochemical properties of the promoted MgO, Li/ MgO,were investigated with SEM,TG,XRD, and CO2-TPD techniques. The results indicated that with increasing the amount of Li from 1 % to 50%, styrene conversion and selectivity to styrene oxide gradually increase. Using 5% Li/MgO,the activity and selectivity can be up to 99.5% and 95.9% ,respectively. Further increase in the amount of Li,the activity and selectivity over Li/MgO basically remained unchanged. These results can be related to the high basicity strength and the amount of strong basic sites on Li/MgO catalysts.
出处
《辽宁师范大学学报（自然科学版）》
CAS
2013年第3期365-368,共4页
Journal of Liaoning Normal University:Natural Science Edition
基金
国家自然科学基金项目(11071031)
关键词
苯乙烯
环氧苯乙烷
过氧化氢
LI
MGO
环氧化
styrene
styrene oxide
hydrogen peroxide
lithium ion doped magnesium oxide
epoxidation
