Continuous production of 1,2-pentanediol from furfuryl alcohol over highly stable bimetallic Ni–Sn alloy catalysts†

The development of robust long-lasting catalysts with enduring activity is essential for the sustainable conversion of biomass into value-added compounds. This study demonstrates the continuous conversion of furfuryl alcohol (FAL) into 1,2-pentanediol (1,2-PDO) using economical bimetallic Ni–Sn/ZnO catalysts. Various Ni/Sn ratios were used to characterize the catalytic surface and ascertain the active sites, revealing a vital collaborative impact between Ni–Sn alloy phases and adjacent SnO_x species. This synergy significantly enhances the targeted breaking of the δ-C₅–O₁ bond in FAL and THFA, leading to continuous and selective 1,2-PDO production. The alteration in the binding energies of Ni and Sn validates the modification in the coordination environment of Ni caused by the transfer of electrons from highly valent Sn. Density functional theory studies combined with experimental results demonstrated that the Ni₃Sn₂ (101) plane promoted the selective synthesis of 1,2-PDO via the THFA dehydrogenation–scission mechanism. Furthermore, the Ni₃Sn₂ phase exhibits superior capability in adsorbing and dissociating H₂ compared with Ni₃Sn and metallic Ni. The representative 3Ni–3Sn/ZnO catalyst demonstrated high efficiency in the continuous conversion of FAL into 1,2-PDO with 91% yield, and a decline in conversion and selectivity was observed after 300 h because of the accumulation of carbonaceous species on the catalytic surface. Notably, a straightforward regeneration process restored the original catalytic activity, enabling the continuous production of 1,2-PDO for a total of ∼450 h, yielding 438 g (4464 mmol) of 1,2-PDO. This advanced catalytic system demonstrates effective scalability in biomass conversion, facilitating environmentally friendly scale-up operation.