Benzotriazolium Ionic Liquid Immobilized on Periodic Mesoporous Organosilica as an Effective Reusable Catalyst for Chemical Fixation of CO2 into Cyclic Carbonates

Abstract

A type of dichloro(dimethoxyethane)nickel anionic benzotriazolium ionic liquid-functionalized periodic mesoporous organosilicas were synthesized and tested as effective and practical heterogeneous catalysts in the cycloaddition of CO2 with epoxides. The catalyst PMO@ILC4H10O2NiCl3(1.0) showed brilliant catalytic activity for the synthesis of cyclic carbonates with high yields and selectivities under solvent-and cocatalyst-free conditions. We also found that the catalytic activity could be significantly influenced by the hydroxyl groups sites of periodic mesoporous organosilica and the active sites (hydroxyl groups/ dichloro(dimethoxyethane)nickel anion) of the benzotriazoliumcation ionic liquid, probably due to an intensification of intramolecular synergistic effect. The catalytic process displayed ease of recovery, excellent stability and recyclability for at least five runs without significant loss of its catalytic activity.

Recent advanced development of metal-loaded mesoporous organosilicas as catalytic nanoreactors

“…In addition, as the aforementioned Co-PMO-IL(x), 150 NiCl 2 (DME) (DME = 1,2-dimethoxyethane) reacted with PMO-IL to form NiCl 3 (DME) − anionic benzotriazolium ionic liquid-functionalized periodic mesoporous organosilicas PMO@ILC 4 H 10 O 2 NiCl 3 with various IL contents. 176 The catalytic activity was evaluated by the cycloaddition of CO 2 with epoxides ( Scheme 13 ). The results showed that catalysts PMO@ILC 4 H 10 O 2 NiCl 3 with various IL contents were effective and practical heterogeneous catalysts in the synthesis of cyclic carbonates with high yields (89.5–97.6%) and selectivities (>99%) under solvent- and cocatalyst-free conditions.…”

“…As the aforementioned PMO@ILC 4 H 10 O 2 NiCl 3 , 176 copper oxychloride (Cu 2 (OH) 3 Cl) was linked to benzotriazolium ionic liquid-modified PMO (PMO-IL) to afford PMO@ILCu 2 (OH) 3 Cl 2 ( x ) ( x represents the amount of IL used in preparation) with ion-type unit –IL + [Cu 2 (OH) 3 Cl 2 ] − . These catalysts were used for the cycloaddition of CO 2 with epoxides.…”