Promotion effect of Fe in the selective hydrogenation of furfural with bimetallic NiFe catalysts

The selective hydrogenation of furfural (FAL) to furfuryl alcohol (FOL) over Ni catalysts offers a sustainable route for biomass valorization. However, the conventional Ni catalysts suffer from poor selectivity in FAL hydrogenation. Herein, we report that the moderate Fe doping in Ni/TiO 2 significantly enhances selectivity without compromising catalytic activity for the selective hydrogenation of FAL to FOL. Notably, Ni/Fe-TiO 2 catalyst with Fe content ≥ 4.9 wt% maintained > 90% selectivity toward FOL at nearly 100% conversion, whereas Ni/TiO 2 achieved only 38% under the identical condition. Combined experimental and theoretical studies revealed that the enhanced catalytic performance of Ni/Fe-TiO 2 originates from the dilution of contiguous Ni sites by Fe, which suppresses the further hydrogenation of FOL. Moreover, Fe sites exhibited a stronger affinity for carbonyl groups compared to Ni(0), indicating complementary role where Ni(0) primarily facilitates H 2 dissociation, while Fe sites play a critical role in carbonyl activation. These findings underscore the superior synergistic effect of bimetallic systems in promoting selective functional group transformation.