Chemical fixation of carbon dioxide to propylene carbonate over amine-functionalized silica catalysts

摘要

Amine-functionalized silica catalysts (NH_2/SiO_2, NH(CH_2)_2NH_2/SiO_2 and 1,5,7-triazabicyclo[4,4,0]dec-5-ene/SiO_2 (TBD/SiO_2)), which were characterized by ~(29)Si NMR, elemental analysis, N_2 adsorption-desorption method and indicator dye adsorption, were prepared by ultrasonic technique under mild conditions. Such hybrid solid bases showed high catalytic activity towards CO_2 coupling with epoxide. However, it was found that the reaction conditions had a great influence on the performance. Furthermore, silanols on the surface played an important role in the chemical fixation of CO_2. Based on these, the possible reaction mechanism was proposed for CO_2 coupling with epoxide over such type of catalysts,