In situ engineering carbon-coated hydrotalcite-derived ZnxAlOy-C catalysts for efficient catalytic transfer hydrogenation of furfural to furfuryl alcohol

Catalytic Transfer Hydrogenation (CTH) has been widely reported as an efficient, safe and green method for catalytic hydrogenation of biomass-derived platform molecules in recent years. In this work, we fabricated tunable Zn/Al molar ratio carbon-coated hydrotalcite-derived Zn-Al oxide composites (Zn_xAlO_y-C), where Isopropanol (IPA) served dual roles as hydrogen donor and reaction medium, to achieve selective hydrogenation of Furfural (FAL) into Furfuryl Alcohol (FOL). Under mild reaction conditions, the conversion of FAL and the selectivity of FOL can reach 92.0% and 93.8% over Zn₂AlO_y-C, respectively. Through analysis, the reasons for the high yield of FOL are that the surface carbon material effectively increases the specific surface area of the catalyst, enhances the adsorption capacity of the catalyst to the reactants, and more effectively promotes the migration of the reactants from the solution to the Zn-O-Al active site, while by adjusting the Zn/Al ratio, a suitable acid/base ratio is found to reduce the occurrence of side reactions and improve the selectivity. The current synthesis method provides an effective way to design carbon-containing composite catalysts with controllable catalytic application performance.