Enhanced bimetallic CuCo nanoparticles on nitrogen-doped carbon for selective hydrogenation of furfural to furfuryl alcohol through strong electronic interactions

Abstract

Bimetallic CuCo catalysts with different Cu to Co ratios on N-doped porous carbon materials (N-C) were achieved using impregnation method and applied in the hydrogenation of furfural (FAL) to furfuryl alcohol (FOL). The high hydrogenation activity of FAL over Cu₁Co₁/N-C was originated from the synergistic interactions of Cu and Co species, where Co⁰ and Cu⁰ simultaneously adsorb and activate H₂, and Cu⁺ served as Lewis acid sites to activate CO. Meanwhile, electrons transfer from Cu to Co promoted the formation of Cu⁺. In situ Fourier transform infrared spectroscopy analysis indicated that Cu₁Co₁/N-C adsorbed FAL with a tilted η¹-(O) configuration. The superior Cu₁Co₁/N-C showed excellent adsorbed ability towards H₂ and FAL, but weak adsorption for FOL. Therefore, Cu₁Co₁/N-C possessed 93.1% FAL conversion and 99.0% FOL selectivity after 5 h reaction, which also exhibited satisfactory reusability in FAL hydrogenation for five cycles.