Highly efficient hydrogenation of furfural to furfuryl alcohol over Cu-Al₂O₃-ZnO catalyst

The development of simple, efficient and economical catalysts for the hydrogenation of biomass to produce high value-added chemicals is of great significance in solving the energy crisis. In this work, a series of non-precious metal catalysts (Cu-Al₂O₃-ZnO) with different defect sites were prepared by etching Devarda's alloy. Under optimized mild reaction conditions, the furfural conversion and furfuryl alcohol selectivity are both greater than 99.0%, and the catalyst has good reusability. Characterisation and experiments were used to investigate the activate species for hydrogenation reaction. It can be proved that the low-valent Cu species in the Cu-Al₂O₃-ZnO catalysts play an important role as adsorption and dissociation sites for H₂. Different etching degrees and sample reduction temperatures of the alloy can be used to adjust the content of acidic sites such as Al₂O₃ and CuO, which have appropriate adsorption properties for furfural. ZnO promotes the dispersion of the Cu species and enhances the accessibility of the active sites. The etching method achieves the interaction between species to further enhance the stability and activity of the catalyst. The catalytic performance of the catalyst is very competitive and this study provides a new method for the efficient hydrogenation of furfural to furfuryl alcohol.