Resourcification of CO2 to high-value-added glycerol carbonate by ZnAlCe composite oxides with frustrated Lewis pairs

Abstract

Zinc-aluminum-cerium composite oxide (ZnAlCe) catalysts were prepared by co-precipitation to catalyze the direct synthesis of glycerol carbonate (GC) from carbon dioxide (CO2) and glycerol. The characterization results showed that the lattice oxygen served as Lewis basic centers and Ce4+ served as Lewis acidic centers on Zn4AlCe catalyst, and frustrated Lewis pairs (FLPs) were formed due to the steric hindrance in the catalyst structure. CO2 was easily activated by FLPs because the acidic and basic centers of FLPs bound to the oxygen and carbon atoms of CO2, respectively. The experimental results indicated that Zn4AlCe catalyst presented excellent catalytic performance with good thermal stability and strong regeneration ability. Under the reaction conditions of 0.115 g catalyst, 12 h, 170 °C, 4.5 MPaCO2 and 5 mL acetonitrile dosage, the GC yield and selectivity were 28.9 % and 51.0 %, respectively. The GC yield is relatively high among similar catalysts reported so far, which lays the foundation for future industrial considerations.