Highly efficient transfer hydrogenation of furfural over Co catalysts at ultra-low loading

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.