Insight into the Synergism between Copper Species and Surface Defects Influenced by Copper Content over Copper/Ceria Catalysts for the Hydrogenation of Carbonate

摘要

Various Cu/CeO2 nanorod catalysts with different copper contents were synthesized through a facile coprecipitation method for the hydrogenation of diethyl carbonate to methanol in a fixed-bed reactor. The methanol yield increased upon increasing the copper loading, but large excess amounts of copper led to deactivation of the catalyst at a high liquid hourly space velocity because of aggregation of the active metal. The 20Cu/CeO2 and 30Cu/CeO2 catalysts displayed superior catalytic performance with methanol space-time yields of 8.4 and 8.1 mmol g(cat)(-1)h(-1), respectively. The remarkably enhanced catalytic performance was mainly ascribed to a high Cu-0 surface area, appropriate ratio of Cu+/Cu-0, and more surface oxygen vacancies associated with Ce3+, which stemmed from a strong interaction between Cu and the CeO2 support.