Ag/SiC和Ag/Al_(2)O_(3)-SiC催化剂的乙烯环氧化催化性能  

Catalytic performances of Ag/SiC and Ag/Al_(2)O_(3)-SiC catalysts for ethylene epoxidation

作　　者：李祥 焦志锋 赵吉晓 魏珍妮 刘宇 郭向云 LI Xiang;JIAO Zhifeng;ZHAO Jixiao;WEI Zhenni;LIU Yu;GUO Xiangyun(School of Petrochemical Engineering,Changzhou University,Changzhou 213164,China;School of Materials Science and Engineering,Changzhou University,Changzhou 213164,China;Lanzhou Petrochemical Research Center,Petrochemical Research Institute,PetroChina Co.,Ltd.,Lanzhou 730060,China)

机构地区：[1]常州大学石油化工学院,江苏常州213164 [2]常州大学材料科学与工程学院,江苏常州213164 [3]中国石油天然气股份有限公司石油化工研究院兰州化工研究中心,甘肃兰州730060

出　　处：《常州大学学报（自然科学版）》2024年第2期85-92,共8页Journal of Changzhou University：Natural Science Edition

基　　金：中国石油常州大学创新联合体资助项目(2021DQ06)。

摘　　要：制备了高分散的Ag/SiC和Al_(2)O_(3)修饰的Ag/SiC催化剂,并用于乙烯环氧化反应。结果显示,Al_(2)O_(3)修饰的Ag/SiC催化剂对乙烯的转化率显著提高,但环氧乙烷的选择性急剧降低。进一步研究发现,在反应过程中乙烯吸附在SiC表面;O_(2)在Ag表面解离后,活性O物种溢流到SiC表面参与环氧化反应。Al_(2)O_(3)修饰后改变了Ag的电子性质,抑制了活性O物种在SiC表面的迁移,导致反应性能的改变。该工作为乙烯环氧化催化剂的设计提供了一定的参考。Highly dispersed Ag/SiC and Al_(2)O_(3)modified Ag/SiC catalysts were prepared and employed for ethylene epoxidation.The results showed that the conversion of ethylene was significantly improved after Al_(2)O_(3)modification,but the selectivity of ethylene oxide was sharply reduced.Further studies revealed that ethylene was adsorbed on SiC surface in the reaction.After O_(2) was dissociated on the Ag surface,the active O species spilled over to SiC surface to participate in the epoxidation reaction.The Al_(2)O_(3)modification altered the electronic properties of Ag and inhibited the migration of active O species on SiC surface,resulting in the change of ethylene epoxidation performances.This work provides some reference for the design of catalysts for ethylene epoxidation.

关 键 词：Ag/SiC催化剂 乙烯环氧化 Al_(2)O_(3)修饰 

分 类 号：O643[理学—物理化学]