Insights Into the one‐Step Dimethyl Ether Carbonylation to Ethanol Over Cu/ZnO@Cu‐MOR Core‐Shell Catalysts with Porogen Engagement

Abstract

AbstractThis study investigates the one‐step ethanol synthesis from dimethyl ether and syngas using the catalysts combining Cu/ZnO oxides and modified Cu‐MOR zeolite. In addition to physically mixed two‐component catalysts, multifunctional catalysts featuring a Cu/ZnO core and modified zeolite (Cu‐MOR and HMOR) shell are also presented. Further, the porogenic agent of dihexadecyldimethylammonium bromide (DHAB) was involved in the synthesis process of the MOR zeolite components of Cu/ZnO@Cu‐MOR and Cu/ZnO/Cu‐MOR catalysts, but not in that of Cu/ZnO@Cu‐MOR° catalyst. A series of characterization measures including XRD, TGA, BET, SEM, TEM and EDS have been systematically studied on the prepared catalysts. Characterizations of the catalyst surface structure and texturing parameters revealed a disturbance in crystallinity upon Cu insertion, facilitating syngas separation and promoting DME carbonylation while preventing undesired CO hydrogenation. The addition of DHAB as a porogen in the synthesis of zeolite shell improved specific surface area and porosity of zeolite shell, and reduced coke deposition, without leaching active metal components, resulting in enhanced reaction properties. Cu/ZnO@Cu‐MOR core‐shell catalyst showed good performance with 28.9 % DME conversion and 43.8 % selectivity for ethanol. The optimized pore structure and enhanced catalytic performance of the modification process validate the effectiveness and efficiency of this strategy.