In this study, single-step synthesis of DME from syngas on bifunctional catalysts containing Cu-ZnO-Al2O3 and seven different zeolites was investigated. Various characterization techniques were used to determine the structure, reducibility, and surface acidity of the catalysts. The experimental results showed that the zeolite type had great influence on the activity, selectivity and stability of the bifunctional catalyst during the syngas-to-DME process. Zeolite properties including density of weak and strong acid sites, pore structure, and Si/Al distribution were found to affect the CO conversion and DME selectivity of the bifunctional catalyst. In addition, the deactivation of the bifunctional catalyst could be attributed to the sintering of metallic Cu and a loss of the zeolite dehydration activity.
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© 2015 The Royal Society of Chemistry.