Trimetallic NiZr/CoOx catalyst for the selective hydrogenation of furfural into furfuryl alcohol

Abstract

Catalytic transfer hydrogenation has attracted great interest as a safe and green method to achieve biomass-based hydrogenation. In this study, a NiZr1/CoOx-400 catalyst was fabricated by in-situ structure topological transformation of layered double hydroxides (LDHs) precursors, which exhibited excellent performance in the in-situ hydrogenation of furfural (FF) using isopropanol as the hydrogen donor, with a maximum FF conversion of 83.5% in only 2 h. According to XRD, XPS and H2-TPR analyses, there was a strong interaction between different metal species in NiZr/CoOx, which increased the surface charge heterogeneity and promoted the phase transition of metal oxides, thereby favoring the generation of oxygen vacancies. Among them, LDHs structure of NiZr1/CoOx-400 catalyst was conducive to expose oxygen vacancies, which could facilitate its interaction with FF. And the Co in the catalyst similarly promoted the adsorption of FF through the coordination of the catalyst surface with the –CHO group in FF, thus contributing to its conversion. The electron-rich Zr repelled the furan ring and prevented the excessive hydrogenation, which improved its selectivity. In addition, the FF hydrogenation followed the quasi-primary kinetics with a low apparent activation energy of 18.4 kJ/mol, which was comparable to that of noble metal catalysts.