Water-mediated hydrogen spillover accelerates hydrogenative ring-rearrangement of furfurals to cyclic compounds

• 1 wt%Pd/NiMoO 4 with different Pd dispersity were synthesized. • Hydrogen spillover process adjusts hydrogenation sites and acidic sites. • 56.3–84.1% yields of cyclopentanones were obtained over Pd/NiMoO 4 -Cl. • 65.4–85.2% yields of cyclopentanols were generated over Pd/NiMoO 4 -AC. • Adsorption configurations of reactants determine the reaction route. Upgrading bioderived furfurals (furfural, 5-hydroxymethylfurfural) to cyclopentanones (cyclopentanone, 3-hydroxymethylcyclopentanone) and cyclopentanols (cyclopentanol, 3-hydroxymethylcyclopentanol) is a representative bifunctional catalytic process in biomass conversion . Here, a class of Pd/NiMoO 4 catalysts (Pd/NiMoO 4 -Cl, Pd/NiMoO 4 -AC) with low Pd loading (1.0 wt%) and different Pd dispersion are synthesized. The hydrogenation active sites and acidic sites of catalysts were adjusted by a water-mediated hydrogen spillover process. 56.3–85.3% yields of cyclopentanones and 65.4–85.2% yields of cyclopentanols were obtained by hydrogenative ring-rearrangement route of furfurals over Pd/NiMoO 4 -Cl and Pd/NiMoO 4 -AC, respectively. Over-hydrogenated byproducts (tetrahydrofurfuryl alcohol, 2,5-bis(hydroxymethyl)tetrahydrofuran) with a yield above 54% were generated by a full hydrogenation route over Pd/C. The difference in catalytic performance is results from alteration of the adsorption configurations of reactants and the transformation of Lewis acid sites to Brønsted acid sites by hydrogen spillover. This work presents an effective strategy for governing reaction routes and enhancing bifunctional catalysis with a hydrogen spillover mechanism.