Catalysts, mechanisms and industrial processes for the dimethylcarbonate synthesis

This review reports on the synthesis of dimethylcarbonate (DMC) and deals with the catalysts, the mechanisms as well as the industrial processes and the reactions for producing DMC, within the policy of developing clean and eco-friendly processes. DMC is considered as an environmentally benign chemical due to a negligible ecotoxicity, a low bioaccumulation and a low persistence, so that the production and chemical use of DMC have attracted much attention in the view of the so-called 'sustainable society' and 'green chemistry', mainly for replacing dimethylsulfate and methylhalides in methylation reactions and for replacing the harmful phosgene in polycarbonate and isocyanate syntheses. Special focus is made on the vapour phase oxycarbonylation of methanol by carbon monoxide in substitution to the old phosgenation process abandoned with years, and as an alternative process to both liquid phase methanol oxycarbonylation and methylnitrite carbonylation processes. The catalytic materials consist in high Surface area active carbon supported copper chloride-based catalysts and chloride-free zeolite catalysts, both investigated in terms of catalyst preparation, active phase nature, performances and catalytic mechanisms. (C) 2009 Elsevier B.V. All rights reserved.