Synthesis driven properties of Ru-Pd nanoalloy for catalytic hydrogenation of levulinic acid with formic acid as hydrogen source in aqueous media

The catalytic hydrogenation of the levulinic acid key platform molecule into γ-valerolactone using formic acid as bio-derived internal hydrogen source is considered as one of the pivotal reactions to convert sustainably lignocellulosic-based biomass into renewable added value chemicals. In this work we present the influence of both the composition and the synthesis methodology on the catalytic activity and properties of Ru-Pd bimetallic catalysts supported on activated charcoal, and particulary the conditions for nano-alloy formation. The Ru-Pd alloy shows high activity in formic acid decomposition and subsequent hydrogenation of levulinic acid in water solvent. The Ru-rich bimetallic catalyst prepared by co-impregnation with final high temperature reduction at 500◦C gave the highest γ-valerolactone yield, thanks to rearrangement and migration of Pd allowing for the formation of the Ru-Pd alloy with isolated (diluted) Pd atoms, and to stabilization of small particle sizes (1.3 nm) which showed high activity in the reaction.