Promoting effect of oxygen vacancies in Co/CoAl2O4 catalyst steered with a straightforward method on hydrogenation of furfural to 2-methylfuran

The exploitation of base metal catalysts to upgrade biomass chemicals remains a daunting challenge and a sustainable strategy. Here, a series of Co-Al spinel catalysts are rapidly prepared by low-temperature solution combustion synthesis for hydrogenation of furfural (FF) to 2-methylfuran (2-MF), in which oxygen vacancies are easily manipulated by regulating the proportion of glycine in the ingredients. The screened Co/CoAl2O4 incorporating adequate oxygen vacancies yields 2-MF over 97 % at 150 ℃ for 5 h, rivalling the state-of-the-art catalysts to date. Characterizations and DFT calculations attribute the success to oxygen vacancies, which not only enhance the adsorption of FF by changing the adsorption geometry, but also facilitate the hydrogen spillover from Co to substrate by moving down the d-band center of CoAl2O4. This study provides a versatile methodology for the efficient and low-temperature preparation of spinel and the construction of defect engineering on catalysts, enlightening the design of phenomenal catalysts.