Direct conversion of furfural to 1,5-pentanediol over a nickel–cobalt oxide–alumina trimetallic catalyst

The use of a Ni–CoOx–Al2O3 mixed metal–metal oxide catalyst was proposed for the one-pot direct conversion of furfural (FFA) to 1,5-pentanediol (1,5-PDO), which afforded a high yield (47.5%) at 160 °C and at an initial H2 pressure of 3 MPa for 6 h in ethanol. Proximity between the Ni0 and oxygen-vacant CoOx (Ov–CoOx) sites favored the dissociative adsorption of H2 molecules on Ni0 and subsequent hydrogen spillover to Ov–CoOx. The hydrogenation of the CO group of FFA produced furfuryl alcohol, which was then adsorbed on the Coδ+ center of the Ov–CoOx site in a η1–(O)–alcoholic configuration, where subsequent C–O bond cleavage produced 1,5-PDO. Catalytic activity loss through the oxidation of the Ni0 and Ov sites could be mitigated by reactivation under H2. Thus, the developed Ni–CoOx–Al2O3 catalyst has potential for efficient, low-cost, and environmentally friendly 1,5-PDO production from FFA.