Catalytic hydrogenation of furfural over Cu/CeO2 Catalyst: The effect of support morphology and exposed facet

The hydrogenation of furfural to furfuryl alcohol in liquid was performed over Cu/CeO2 catalyst with different morphology that was nanorod (CeO2-R), nanocube (CeO2-C) and nanopolyhedron (CeO2-P), respectively. It was observed that the Cu/CeO2-R catalyst exposed (1 1 0) crystal plane owns more oxygen vacancies and metal sites of Cu0 in comparison with the catalyst of Cu/CeO2-P and Cu/CeO2-C. Meanwhile, it exhibited superior catalytic performance for furfural hydrogenation to furfuryl alcohol with a high yield of 98 % at 100 °C, 2 MPa H2 within 4 h. The structure–activity relationship demonstrated that the catalyst intrinsic activity (TOF) is positively related to the concentration of oxygen vacancies and the metal sites of Cu0 on its surface. DFT calculations and in-situ FTIR confirmed that Cu/CeO2-R (1 1 0) catalyst with more oxygen vacancy is in favor of the adsorption and activation of furfural (CO) on the catalyst surface compared with Cu/CeO2-P (1 1 1) and Cu/CeO2-C (1 0 0). Accordingly, the remarkable efficiency of Cu/CeO2-R catalyst can be assigned to the synergistic catalysis between the surface Cu0 and the oxygen vacancies. Cu0 was used to adsorb and activate H2, whereas the oxygen vacancies facilitate the adsorption of CO by O on the surface of the catalyst.