SBA-15 supported pyrazolium ionic liquid efficient fixation of carbon dioxide into cyclic carbonate under mild conditions: The synergistic contribution of SBA-15 and pyrazolium ionic liquid

Immobilized ionic liquids are one of the most popular catalysts for the cycloaddition of carbon dioxide (CO 2 ) and epoxides with some distinguished advantages. However, the harsh reaction condition, especially for the high reaction pressure, is still the obstacle for its large-scale application. A series of amino-functionalized pyrazolium ionic liquids are grafted on SBA-15 in this work. Among them, SBA-15-APMPzBr(20) exhibits the best catalytic activity achieving 97.6% product yield under 0.5 MPa CO 2 pressure at 100 °C by using 100 mg SBA-15-APMPzBr(20) for 10 h. No solvent is added in the catalytic system. Moreover, SBA-15-APMPzBr(20) exhibits the good recyclability and generality. Its excellent catalytic performance is attributed to the contribution from both immobilized ionic liquids and the SBA-15 supporter. Besides the mesoporous feature, the hydroxyl groups in SBA-15 promote the ring-opening of substrate, which is testified by the experimental measurements and density functional theory calculations.