Efficient Pt1Ni single-atom alloy catalyst for hydrogen-free catalytic fractionation of lignocellulose

The production of monophenols from lignocellulose with cellulose intact without exogenous hydrogen via self-hydrogen supplied fractionation is promising, yet requires high metal loadings and yields saturated products. Herein, we report a single-atom alloyed Pt1Ni catalyst that achieves 50.9 wt% yield of phenolic monomers from birch sawdust with about 50% selectivity to valuable propenyl side-chained products under mild conditions (140 °C, 1 atm N2), while preserving cellulose intact. Reaction pathway studies and density functional theory calculations based on a β-O-4 model compound reveal three coexisting pathways. The Pt1Ni alloy preferentially promotes the dehydroxylation of Cα-OH and forms a key Cα = Cβ intermediate due to the oxygen affinity of Ni sites, and ultimately, enhance the production of valuable propenyl products via the synergistic effect of Pt and Ni. This work provides a strategy for maximizing Pt utilization and producing unsaturated chemicals from biomass under hydrogen-free conditions, advancing sustainable biorefining. Making phenols from lignocellulose without added hydrogen is attractive but typically requires high metal loadings and yields mostly saturated products. A single-atom Pt1Ni alloy converts birch sawdust to phenolic monomers with high yield and propenyl selectivity while leaving cellulose intact.