Highly efficient synthesis of dimethyl carbonate from methanol and carbon dioxide using IL/DBU/SmOCl as a novel ternary catalytic system

摘要

Excellent yield of dimethyl carbonate (DMC) was obtained by direct physical or chemical adsorption of carbon dioxide on [EmimOH][NTf2] ionic liquid (IL) in the presence of samarium oxychloride (SmOCl) and 1,8-diazabicyclo[2.2.2]undec-7-ene (DBU) as a super base. The novel ternary catalyst system consisting of [EmimOH][NTf2], DBU, and SmoCl was found to appreciably convert methanol (13.01%) to DMC with excellent selectivity (99.13%). The adsorption of CO2 on IL in the presence of DBU was analyzed by C-13 experiment. Moreover, catalytic reactivity of SmOCl and OH-functional group was proved by a predictable mechanism. Various parameters such as reaction temperature, pressure, reaction time, and reusability of catalyst were investigated to maximize DMC yield. (C) 2015 Elsevier B.V. All rights reserved.