Novel ZrFe2ZnO6 with multiple functional composite supports for one-step synthesis of diethyl carbonate from CO2 and ethanol

Abstract

The yield of the synthesis of diethyl carbonate only from CO₂ and ethanol is ca. 5–15% unless an expensive third monomer is added. To the best of our knowledge, this work represents the first report of the DEC yield exceeding 50% without adding a third monomer. A multiple functional composite support “@3A-CaO–CaC₂” is the key to the huge increase of the DEC yield. The yield was 3.93% when catalyzed by Fe₂O₃–ZrO₂–ZnO (1 : 1 : 1) while the yield was 57.7% when catalyzed by 15 wt% Fe₂O₃–ZrO₂–ZnO@3A-CaO–CaC₂. 3A provided a strong skeleton network and physically removed water; CaO played a role in chemically removing water; CaC₂ played a role in chemically removing water rapidly. Our results suggest that chemical water removal has a more significant effect than physical water removal. Moreover, the water removal rate rather than water removal capacity is the key to increase the DEC yield. In summary, the contribution of this work is that the multifunctional composite carrier realizes the function of in situ water removal, thus greatly improving the efficiency of the catalyst from 3.93% up to 57.7%.