Abstract
BACKGROUND: Dimethyl carbonate (DMC) can be used effectively as an environmentally benign substitute for highly toxic phosgene and dimethyl sulfate in carbonylation and methylation, as well as a promising octane booster owing to its high oxygen content. Twoβstep transesterification from epoxide, methanol, and CO~2~ is widely used in the bulk production of DMC. However, major disadvantages of this process are high energy consumption, and high investment and production costs. A one pot synthesis of DMC from carbon dioxide, methanol, and epoxide was, therefore, developed. But the yields of DMC are below 70% due to the thermodynamic limitation.
RESULTS: Electrochemical synthesis of DMC was conducted with platinum electrodes from methanol, CO~2~ and propylene oxide in an ionic liquid was conducted. The bmimBr (1βbutylβ3βmethylimidazolium bromide)βmethanolβpropylene oxide system with CO~2~ bubbling allows DMC to be effectively synthesized and a high yield (75.5%) was achieved.
CONCLUSION: In this electrolysis, redox reactions of substrates, CO~2~, methanol, and propylene oxide, on Pt electrodes were carried out, producing the activated particles, CH~3~O^β^, CH~3~OH^+^, CO~2~^β^ and PO^β^, resulting in the effective synthesis of DMC with a 75.5% yield in an ionic liquid (bmimBr). Finally, a mechanism for this synthesis reaction was proposed, which is very different from those reported in the literature. Copyright Β© 2011 Society of Chemical Industry