Single‐Step Synthesis of Dimethyl Ether from Syngas over Nanoparticle‐Derived Bifunctional Pd/CeO <sub>2</sub> /Al <sub>2</sub> O <sub>3</sub> Catalysts
Bing Wang, Zairan Yu, Shuang Chen, Nicola Da Roit, Dieter Schild, Michael Zimmermann, Yuemin Wang, Silke Behrens
Abstract
Abstract The single‐step syngas‐to‐dimethyl ether (STD) process offers both economic and technical advantages over the current two‐step industrial process that utilizes Cu/ZnO/Al 2 O 3 catalysts. Here, we report a highly active bifunctional Pd/CeO 2 /γ‐Al 2 O 3 catalyst, in which Pd colloids dispersed in a nanoscale CeO 2 matrix serve as the key building block for the methanol‐active component, efficiently catalysing the STD reaction. For Pd/CeO 2 /γ‐Al 2 O 3 with a high Pd‐CeO 2 interface concentration, CO conversion and dimethyl ether yield are significantly increased compared to Pd supported on Al 2 O 3 . Systematic investigations using spectroscopic and microscopic techniques reveal the formation of highly dispersed palladium clusters/particles confined within the nanoparticulate CeO 2 matrix. The superior catalytic performance in both activity and stability observed for the Pd/CeO 2 /γ‐Al 2 O 3 in the STD reaction stems from the active cationic palladium interfacial species and the presence of adjacent O vacancies.