Abstract: In this paper，the catalysis and mechanism of ionic liquids for direct synthesis of dimethyl carbonate(DMC) is studied. Though the ionic liquids that have no catalysis and do not change the reaction law，but it is the method for promoting the reaction and the yield of DMC，just because of their good dissolution with carbon dioxide，methanol and DMC .Under the best reaction condition，363K，3.6MPa，8h，and 12/2.3/1.6/1 that mass ratio of CH3OH/ CH3I/[Emim]Br/K2CO3，the yield of DMC could be enhanced from 5.52(wt%) to 6.46(wt%) by [Emim]Br ionic liqiud.

摘要： 考察了多种离子液体对直接合成碳酸二甲酯(DMC)反应的促进作用，并对机理作了分析。结果表明，离子液体对反应几乎没有催化活性，但有明显的促进作用，是提高DMC收率的一种新途径，反应的规律和历程不发生改变；离子液体对CH3OH、DMC和CO2有良好的溶解性，是促进作用的主要原因；其中，溴代1–乙基–3–甲基咪唑盐[Emim]Br在363 K、3.6 MPa、反应时间8 h和m(CH3OH)/m(CH3I)/m([Emim]Br)/m(K2CO3)为12/2.3/1.6/1的条件下，可使DMC质量分数由5.52%提高到6.46%。