Research Progress in Catalysts for Direct Carbonylation of Glycerol with CO2 to Glycerol Carbonate
The direct carbonylation of glycerol with CO2 to glycerol carbonate represents a promising route for CO2 utilization, addressing both carbon emission reduction and the synthesis of value-added chemicals. However, the reaction is thermodynamically limited, resulting in low glycerol conversion, necessitating the use of coupling agents and appropriate catalysts. This review systematically examines recent progress in homogeneous catalysts (inorganic and organic bases) and heterogeneous catalysts (Zn, Cu, Ce, La, Mg, noble metals, modified zeolites, non-metallic materials) for this transformation. Strategies such as metal oxide modification, support optimization, precursor selection, and construction of acidic-basic sites are analyzed for enhancing catalytic performance. The effects of coupling agents including acetonitrile, adiponitrile, 2-cyanopyridine, MgCO3, CaC2, and NaHCO3 are summarized. Notably, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), Zn(QTf)2, and metal composite oxides like ZnO-CeO2 have demonstrated promising catalytic performance. Future research directions include developing organometallic complexes or composite metal oxides with highly dispersed active sites and tailored morphologies to modulate surface area, pore size, and acidity/basicity; optimizing coupling agents or designing novel membrane reactors to improve glycerol conversion; and introducing polar solvents to enhance reactant adsorption and activation. These approaches provide valuable references for catalyst design and reaction system optimization in the carbonylation of glycerol with CO2.