Review on the synthesis of dimethyl carbonate

Dimethyl carbonate (DMC, (CH3O)2CO), as an important and environmentally friendly chemical intermediate, has been widely used in industrial fields. Several large-scale industrial routes of DMC production, e.g., phosgene route, transesterification route, and the liquid-phase oxidative carbonylation of methanol, have been developed to date. Nevertheless, these industrial routes suffer from different drawbacks, such as the use of hypertoxic phosgene as raw material, high production cost, and explosion risk. Currently, vapor-phase methyl nitrite (MN) carbonylation to DMC, a route developed by the UBE Company, can be the most promising new-generation industrial route. This route exhibits many advantages, including environmental friendliness, low cost, and high efficiency. The key to industrialization is the development of an efficient and stable catalyst. Heterogeneous supported Pd-based catalysts have been widely investigated in this system. In this review, we provide detailed introduction regarding the existing DMC synthesis methods and the vapor-phase MN carbonylation to DMC route with related catalyst research progress. Opportunities and challenges for synthesizing DMC are also presented.