An ultra-low loading (0.08 wt.%) cobalt single-atom catalyst, synthesized by the adsorption of trace amounts of cobalt salt onto a zeolitic imidazolate framework-8 (ZIF-8) precursor, followed by pyrolysis under Ar at 800 °C, exhibits exceptional performance in the catalytic transfer hydrogenation of furfural to furfuryl alcohol. Under optimized conditions (120 °C, 6 h), the catalyst achieved complete furfural conversion and a selectivity of 96.5% toward furfuryl alcohol. Remarkably, its turnover frequency (TOF) reached 1290.6 h⁻¹, which is three to four orders of magnitude higher than that of previously reported single Co catalysts. The superior catalytic activity is attributed to the uniformly dispersed Co-N₄ matrix and abundant weak and moderate acid sites. Furthermore, Co-ZIF-8-800 exhibited broad substrate scope via the Meerwein–Ponndorf–Verley (MPV) mechanism. This work provides a promising strategy for designing low-cost and highly efficient non-noble metal catalysts for the conversion of biomass-derived platform molecules.

Hydrodeoxygenation (HDO) is vital important for the valorization of oxygen-rich biomass derivatives into high-energy-density fuels and valuable chemicals by selective removal of oxygen-containing functional groups. Low-cost NiFe-based bimetallic catalysts, which integrated the excellent hydrogen activation ability of Ni with the selective adsorption and cleavage of oxygen-containing functional groups of Fe, were attractive in HDO of biomass. However, the limited insights into the coordination structures of active sites and the effects of heteroatom-doping hindered the in-depth understanding of structure−activity relationship in HDO. Herein, a highly selective Ni-280/Fe-N-C-800 catalyst was fabricated via two-step pyrolysis, which afforded 96.3% 2,5-dimethylfuran (DMF) selectivity and complete 5-hydroxymethylfurfural (HMF) conversion at 240 °C and 4 MPa H₂, comparable to state-of-the-art catalysts. More importantly, comprehensive characterizations and fruitful experimental results combined with DFT calculations confirmed that the Fe-N₄-assisted NiFe alloy nanoparticles (NPs) served as the core active sites, then promoting by metal (M)-N_x coordination structures. This work not only elucidated the structure−activity relationship between NiFe alloy catalysts and reactants, but also provided theoretical guidance for selectivity control in HDO process.