Direct Carbonation of Glycerol with CO₂ Catalyzed by Metal Oxides

Abstract

Five metal oxides (ZnO, SnO2, Fe2O3, CeO2, La2O3) were produced by the sol–gel method and tested in the direct carbonation of glycerol with CO2. Initial tests with Fe2O3 showed that the best reaction condition was 180 °C, 150 bar, and 12 h. The other oxides were evaluated at these conditions and were all active to the formation of glycerol carbonate. Zinc oxide was the most active catalyst, with a yield of 8.1 % in the organic carbonate. The catalytic activity decreased upon washing and drying the ZnO catalyst between the runs. Nevertheless, the activity is maintained if the ZnO is washed and calcined at 450 °C between the runs. FTIR and TGA results indicated the formation of ZnCO3 as the main cause of catalyst deactivation, which may be decomposed upon calcination of the material. No appreciable leaching of Zn was observed, indicating a truly heterogeneous catalysis.

Recent progress in the catalytic transformation of carbon dioxide into biosourced organic carbonates

“…Up to now, many catalytic systems have been reported that are based on metal oxides/complexes, [52][53][54][55][56][57] supported metal catalysts, 58,59 or modified zeolites or hydrotalcites, [60][61][62] in combination with a dehydrating reagent. Most of the reported heterogeneous catalysts typically require harsh reaction conditions for GC synthesis, i.e.…”

Improving Product Yield in the Direct Carboxylation of Glycerol with CO2 through the Tailored Selection of Dehydrating Agents

“…In order to overcome thermodynamic limitations, basic dehydrating agents can be used to remove water and shift the equilibrium to the product side. In the absence of dehydrating agents, the reaction achieves only low yields, e.g., over metal impregnated zeolites, at 100 bar, a 6% yield of glycerol carbonate was achieved [22]; while an 8% yield of glycerol carbonate was observed upon the introduction of ZnO at 150 bar [23]. Higher yields have been achieved when conducting the reaction in methanol as a solvent, with George and co-workers observing a 35% yield at 138 bar [24].…”

An Overview of the Latest Advances in the Catalytic Synthesis of Glycerol Carbonate

“…Under certain reaction conditions, both CO 2 and CO can be used as carbonylation reagents to react with glycerol to generate GC, but compared with CO 2 , CO has higher chemical activity. In the reaction of glycerol and CO to produce GC, the most common oxidant is oxygen, which can afford GC in high yield under relatively mild conditions [52].…”