Catalytic systems for the direct synthesis of dimethyl carbonate from carbon dioxide and methanol containing dehydrating agent, a review

Dimethyl carbonate (DMC) is a widely used environment-friendly green chemical, and the direct synthesis of DMC from CO₂ and CH₃OH has become one of the research focuses on the clean conversion of CO₂ in recent years. The design of efficient and stable catalysts and reaction processes to promote the conversion of CO₂ is the key to realize the direct synthesis of DMC in industry. In this paper, the research progress of catalytic systems for the direct synthesis of DMC from CO₂ and CH₃OH is reviewed and the reaction mechanism of different types of catalysts is summarized, mainly including the ionic liquid catalyst, alkali metal carbonate catalyst, transition metal oxide catalyst, etc. The operation principle of various dehydrating agents and their promoting effect on the production of DMC are expounded, while the advantages and disadvantages of different catalytic-dehydration systems are analyzed. It is predicted that the development of efficient and stable catalysts and membrane materials with strong permeability to water as well as the construction and implementation of new dehydration processes will be the focus of future research on the direct synthesis of DMC from CO₂ and CH₃OH.