碱金属碳酸盐改性对Au/TS-1催化剂的丙烯气相环氧化活性和稳定性的提升作用研究  

Enhancement of the activity and stability of Au/TS-1 catalyst in the gas-phase epoxidation of propene through alkali carbonate modification

作　　者：伏劲松 梁武洋[1,2] 雷骞 孙冰[4] 陈洪林[1] 张小明[1] FU Jin-song;LIANG Wu-yang;LEI Qian;SUN Bing;CHEN Hong-lin;ZHANG Xiao-ming(Chengdu Institute of Organic Chemistry,Chinese Academy of Sciences,Chengdu 610041,China;University of Chinese Academy of Sciences,Beijing 100049,China;College of Chemistry and Materials Science,Sichuan Normal University,Chengdu 610068,China;Sinopec Research Institute of Safety Engineering,Qingdao 266000,China)

机构地区：[1]中国科学院成都有机化学研究所,四川成都610041 [2]中国科学院大学,北京100049 [3]四川师范大学化学与材料科学学院,四川成都610068 [4]中国石化化工股份有限公司青岛安全工程研究院,山东青岛266000

出　　处：《燃料化学学报》2020年第10期1256-1262,I0007,共8页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金(21606258)资助。

摘　　要：制备了不同碱金属碳酸盐(Na2CO3、K2CO3、Rb2CO3和Cs2CO3)超声浸渍改性的Au/TS-1催化剂,采用XRD、ICP、XPS、UV-vis、NH3-TPD、FT-IR和HAADF-STEM等手段对催化剂结构性质进行了表征,研究了碱金属碳酸盐改性对Au/TS-1催化剂的丙烯气相环氧化活性和稳定性的影响。结果表明,碱金属碳酸盐改性可以降低Au/TS-1催化剂的表面酸性,减缓环氧丙烷(PO)在催化剂表面吸附引起的积炭失活,抑制金颗粒粒径的增大;此外,Cs2CO3和Rb2CO3改性还可减少Au/TS-1催化剂上的骨架外Ti含量。碱金属碳酸盐改性后的Au/TS-1的催化活性和稳定性都得到明显的改善,其中,Cs2CO3改性的Au/TS-1表现出最佳的催化活性,丙烯转化率为6.2%,环氧丙烷选择性为86.2%,氢气利用效率为26.2%。相关研究为提高Au/TS-1催化剂的丙烯气相环氧化活性和稳定性提供了新的思路。A serious of robust Au/TS-1 catalysts were prepared by modifying with various alkali carbonates including Na2CO3,K2CO3,Rb2CO3 and Cs2CO3 via the ultrasonic impregnation.The alkali carbonate-modified Au/TS-1 catalysts were characterized by XRD,ICP,XPS,UV-vis,FT-IR,NH3-TPD and HAADF-STEM and their catalytic activity and stability in the gas-phase epoxidation of propene were investigated in a fixed-bed reactor in the presence of H2 and O2.The results indicate that the modification with alkali carbonates can decrease the surface acidity and inhibit the aggregation of Au particles;moreover,Rb2CO3 and Cs2CO3 can even reduce the content of extra-framework Ti in Rb-Au/TS-1 and Ce-Au/TS-1.The catalytic activity and stability of Au/TS-1 in the gas-phase epoxidation of propene are significantly improved after the modification with alkali carbonates.In particular,Cs2CO3-modified Cs-Au/TS-1 catalyst exhibits the best performance,with a propene conversion of 6.2%,selectivity of 86.2%to propene oxide(PO)and H2 utilization efficiency of 26.2%.The results suggest that alkali carbonate modification could be a novel strategy to enhance the catalytic activity and stability of Au/TS-1 in propene epoxidation.

关 键 词：碱金属碳酸盐 Au/TS-1催化剂 丙烯环氧化 超声浸渍 活性和稳定性 

分 类 号：O69[理学—化学]