Highly Active and Selective NiFe/SiO₂ Bimetallic Catalyst with Optimized Solvent Effect for the Liquid-Phase Hydrogenation of Furfural to Furfuryl Alcohol

Abstract

Toxic Cu–Cr catalysts or precious metal catalysts are currently used for the selective hydrogenation of biomass-derived furfural to the key intermediate furfuryl alcohol (FFA). Herein, efficient and Cr-free Ni-based nonprecious bimetallic catalysts were developed. Catalyst characterizations with XRD, TEM, and TPR and catalytic evaluation revealed that the Ni3Fe1/SiO2 catalyst showed a significant synergetic effect. Compared with the Ni/SiO2 monometallic catalyst, the activity increased by 8 times, and the selectivity to FFA increase from 50% to 91.7% over the Ni3Fe1/SiO2 bimetallic catalyst. Furthermore, the solvent effect is significant in terms of catalytic activity and product distribution. Protic solvents, especially alcohols, showed the highest reaction rate and FFA selectivity. The byproduct tetrahydrofurfuryl alcohol, which is produced by excessive hydrogenation, was almost completely inhibited due to competitive adsorption when using methanol as solvent. At optimized operating conditions, the Ni3Fe1/SiO2 catalyst showed 100% conversion and 96.5% selectivity to FFA in methanol solvent with a good recyclability, which was much better than most reported catalysts.