Synthesis of dimethyl carbonate from transesterification of ethylene carbonate with methanol using immobilized ionic liquid on commercial silica

Ionic liquid immobilized on commercial silica catalysts proved to be an effective heterogeneous catalyst for the synthesis of dimethyl carbonate (DMC) from transesterification of ethylene carbonate (EC) with methanol. The immobilized 1-n-alkyl imidazolium halide ionic liquid on commercial silica (RImX-CS) was characterized by EA, BET, FT-IR, C-13 NMR and Si-29 NMR. It was found that RImX-CS with a longer alkyl chain length showed much better catalytic activity. RImX-CS with chloride (Cl-) as the counter anion showed the best catalytic activity. High temperature, high carbon dioxide pressure, and longer reaction time were favorable for the reactivity of BulmBr-CS. The catalyst can be reused for the reaction up to three consecutive runs without any considerable loss of its initial activity.