Investigating the reaction mechanism of dimethyl carbonate synthesis through isotopic labeling experiments

Abstract

The synthesis of dimethyl carbonate (DMC) from carbon dioxide and methanol was studied over a ceria- zirconia mixed metal oxide. When using oxygen-18 labeled ceria-zirconia, no oxygen-18 labeled DMC or water was observed. On the other hand, using oxygen-18 labeled methanol led almost exclusively to the formation of double labeled DMC, CH318O (C16O) 18OCH3. These results were used to further elaborate the proposed reaction mechanisms for DMC synthesis. The rate-controlling step identified was that of a nucleophilic attack of gas phase methanol on surface monomethyl carbonate species to form DMC.

Keywords

• Oxygen-18
• Methanol
• Carbon dioxide
• Ceria–zirconia
• Reaction mechanism