Synthesis of bi-functionalized ionic liquid — mesoporous alumina composite material and its CO2 capture capacity

Abstract

Bi-functionalized ionic liquid (IL) — mesoporous alumina (MA) composite material was synthesized and used for CO2 capture. Ordered mesoporous alumina was synthesized by self-assembly method with aluminum isopropoxide as aluminum source. Then bi-functionalized ionic liquid 1-methoxyethyl-3-methyl imidazole glycinate ([MOEmim][Gly]) was immobilized on mesoporous alumina by ultrasonic-assisted impregnation method. Ordered mesostructure of alumina keeps well in the composite material. Compared with bi-functionalized ionic liquid, thermal stability of the composite material greatly improved. Finally, CO2 capture capacity of IL-MA composite material was studied under different temperatures. On the basis of both capture capacity and capture rate, 40 ·C is the optimal temperature. The capture capacity is 1.42 mol·mol IL−1 — equivalent to 144 mg·g sorben−1, which is higher than IL or MA alone. Furthermore, the capture capacity of composite material almost maintains constant after eight capture-regeneration cycles.