Mechanistic insights into the catalytic hydrogenation of furfural derivatives over Pd and Pt catalysts

• An experimentally validated DFT study clarifies hydrogenation pathways of furfural-derived ketones on Pd(1 1 1) and Pt(1 1 1). • Chain C C bonds hydrogenate easily on both metals, while furan ring hydrogenation varies significantly depending on the catalyst. • Pd(1 1 1) exhibits a low activation barrier (+69.1 kJ mol −1 ) and charge-driven selectivity toward ring hydrogenation. • Charge buildup on furan carbons hinders ring reduction on Pt(1 1 1). • Charge distribution is identified as a predictive marker for catalyst performance in bio-based hydrogenation. Furfural derivatives are promising bio-based platform molecules for the sustainable production of fuels and chemicals, yet their selective hydrogenation remains highly sensitive to catalyst choice. Here, we combine density functional theory (DFT) calculations with kinetic experiments to elucidate the mechanisms governing the hydrogenation of a furfural-derived α,β-unsaturated ketone, (E)-1-(furan-2-yl)-5-methylhex-1-en-3-one, over Pd and Pt catalysts. Periodic DFT calculations on Pd(1 1 1) and Pt(1 1 1) surfaces reveal low activation barriers for α-hydrogenation of the chain C C bond on both metals, in agreement with the rapid and selective formation of the partially hydrogenated product observed experimentally. In contrast, hydrogenation of the furan ring is strongly metal-dependent. Over Pd(1 1 1), ring hydrogenation proceeds with relatively low barriers and limited charge accumulation on the ring carbons, enabling efficient conversion to the fully hydrogenated product. Over Pt(1 1 1), however, ring hydrogenation is associated with higher activation energies, significant positive charge accumulation, and weaker adsorption of hydrogenated ring intermediates. Kinetic experiments over supported catalysts reveal distinct reaction regimes consistent with these predictions. While Pt catalysts exhibit transient formation of the fully hydrogenated product at early reaction times, the subsequent evolution of product yields is non-monotonic, reflecting reversible surface-mediated interconversion between partially and fully hydrogenated adsorbates in the presence of adsorbed hydrogen. At longer reaction times, secondary reactions further suppress net ring hydrogenation on Pt. Overall, this work demonstrates that charge redistribution and adsorption strength jointly control hydrogenation selectivity in furfural derivatives and provides mechanistic descriptors for the rational design of catalysts for biomass upgrading