Direct synthesis of dimethyl carbonate from methanol and carbon dioxide was studied over heterogeneous catalysts. It is found that dimethyl carbonate can be synthesized selectively on zirconia catalysts. The additive effect of phosphates or sulfates to zirconia was investigated. Phosphoric acid was found to be very effective for the enhancement of the catalytic activity with high selectivity in this reaction. On zirconia and phosphoric acid-modified zirconia catalysts, the amount of by-products, dimethyl ether and carbon monoxide was below the detection limit. This reaction proceeded at much lower temperature on phosphoric acid-modified zirconia than on unmodified zirconia. It is suggested that DMC formation proceeds on the active sites derived from the interaction between phosphoric acid and zirconium hydoxide during the catalyst preparation.
ASJC Scopus subject areas
- Chemical Engineering(all)