Rational design for the fabrication of bulk NiSn alloy catalysts for the synthesis of 1,4-pentanediol from biomass-derived furfural without acidic co-catalysts.

This study describes the rational design for the fabrication of bulk NiSn alloy catalysts for the de/hydration-hydrogenation of biomass-derived furfural (FFald) to 1,4-pentanediol (1,4-PeD) without the acidic co-catalyst. The presence of both hydration active sites (Brønsted acid sites (Ni-SnO)) and hydrogenation active sites (Ni or Ni-Sn alloy) in NiSn alloy could be controlled by changing the pH of Ni-Sn solution during the preparation. Both active sites acted synergistically to catalyse the de/hydration-hydrogenation reactions of FFald to produce a high yield of 1,4-PeD in a batch reaction system at 433 K, 3.0 MPa H after 12 h. Bulk NiSn obtained at pH of Ni-Sn solution of 8-10, hydrothermal temperature of 423 K for 24 h, and reduction with H at 673 K for 1.5 h demonstrated a high yield of 1,4-PeD (81-87%), which is comparable with that from previous work. A 76% yield of 1,4-PeD was also obtained when the reaction was carried out in a fixed-bed reaction system at 433 K, flow rate 0.065 mL min, H flow rate 70 mL min, and 3.29 wt% FFald in HO/ethanol solution for 12 h. The activity of bulk NiSn was maintained with 66% yield of 1,4-PeD even after 52 h reaction on stream. The fabricated bulk NiSn alloy catalysts could be the promising heterogeneous Ni-Sn alloy-based catalysts for the catalytic conversion of biomass-derived-furanic compounds (, FFald, furfuryl alcohol (FFalc), and 2-methylfuran (2-MeF)).