Synergy between Ni3Sn2 alloy and Lewis acidic ReOx enables selectivity control of furfural hydrogenation to cyclopentanone

Selectivity controlling is a crucial and challenging issue for the hydrogenation of furfural (FAL) to cyclopentanone (CPO). Herein, Ni3Sn2-ReOx/TiO2 is synthesized via successive impregnation and exhibits full conversion and 92.5% CPO selectivity under 3.0 MPa H2 at 140 °C, which are much higher than those of Ni/TiO2 and Ni3Sn2/TiO2. Characterizations show that Ni3Sn2 is the main active phase that remarkably restrains the over-hydrogenation of the furan ring, while ReOx plays an electrophile or Lewis acid site to activate C-OH of furfuryl alcohol and induces its rearrangement. DFT calculations verify that Sn doping weakens the furan ring adsorption on Ni3Sn2 and shifts its adsorption configuration, which consequently inhibits side reactions and favors the metal-acid (Ni3Sn2-ReOx) synergy. The catalyst is stable, recyclable and also active at even 0.5 MPa H2 and 80 oC. This study provides an advanced strategy for the rational design of superior catalysts for tuning product selectivity, with practical potential for upgrading biomass-derived platform molecules.