Isomerization of 5-Vinyl-2-norbornene Using Sodium-coated Catalysts

摘要

Various sodium-coated metal oxide catalysts were prepared using readily available supporting materials such as neutral gamma-Al2O3(neutral alumina,N-Al2O3)basic gamma-Al2O3(basic alumina,B-Al2O3),SiO2,MgO,and TiO2,and their catalytic activities were evaluated for the isomerization of 5-vinyl-2-norbornene(VNB)to 5-ethylidene-2-norbornene(ENB).Of various sodium-coated catalysts,Na/N-Al2O3 and Na/B-Al2O3 showed extremely high activities,resulting in quantitative conversion of VNB.Catalyst characterization and isomerization results clearly demonstrated that the presence of both strong basic sites(PK_(BH)>=27)and one-electron donor sites on the Na/Al2O3 is prerequisite for the isomerization of VNB to take place.