Harnessing CO 2 into Carbonates Using Heterogeneous Waste Derivative Cellulose-Based Poly(ionic liquids) as Catalysts

Abstract

CO 2 chemical transformation into chemicals is an interesting option to mitigate CO 2 concentration in the atmosphere. CO 2 is an important carbon source, non-toxic, non-flammable, abundant and renewable, making it an interesting raw material. In this work, cellulose-based poly(ionic liquids) (CPILs) was synthesized from cellulose extracted from rice husk, modified with citric acid and functionalized with different cations. CPILs were used as heterogeneous catalysts for CO 2 chemical transformation into cyclic carbonates by cycloaddition of CO 2 with epoxides [propylene (PO) and styrene oxides (SO)]. The effect of the cation present in CPILs in catalytic performance, use of ZnBr 2 as a co-catalyst and catalytic reaction parameters (temperature, pressure and time) were investigated just as well. Results demonstrate that CPILs cation variation influence their catalytic activity. A higher CO 2 yield and selectivity of 81.9%/95.3% for propylene carbonate (PC) and 78.7%/100% for styrene carbonate (SC) was obtained by CPIL-TBP/ZnBr 2 at conditions of 40 bar, 110 °C and 6 h, being easily separated and recycled without significant loss of catalytic activity until the fourth cycle.