Abstract:
The process route for producing ethanol via carbon-containing resources (coal-derived) syngas through dimethyl ether (DME) carbonylation to methyl acetate (MA), followed by MA hydrogenation, offers advantages such as mild reaction conditions and the use of cost-effective, easily prepared catalysts. This pathway represents a significant approach for achieving clean and efficient coal utilization, as well as promoting the transformation of coal into high-value chemicals. The DME carbonylation reaction serves as the core step of this process, and the application of zeolite catalysts in DME carbonylation has attracted widespread attention. This review summarizes recent advances in the understanding of the reaction pathways and deactivation mechanisms of zeolite catalysts in DME carbonylation. It discusses the application of various zeolites, particularly mordenite, in DME carbonylation and clarifies the nature of the active sites in zeolite catalysts. Building on the understanding of reaction pathways, deactivation mechanisms, and active sites, the review further outlines modification strategies for zeolite catalysts. These strategies primarily aim to precisely regulate the number and spatial distribution of active centers, effectively inhibit the acid sites responsible for coke formation, and enhance the mass transfer efficiency by optimizing the crystal size or pore structure. Specific discussions cover three main aspects: acid site regulation, microstructural modulation, along with summaries of research findings related to catalyst regeneration, optimization of preparation conditions, and industrial molding technologies. Finally, based on a summary of existing research, the review identifies current challenges and outlines future research directions for zeolite catalysts in DME carbonylation.