Enhanced hydrogenation of ethyl levulinate by Pd–AC doped with Nb2O5

Abstract

Gamma-valerolactone (GVL), as sustainable feedstock for high-value chemicals and fuel, has been produced by hydrogenation of levulinic acid (LA) or ethyl levulinate (EL). In this work, Pd nanoparticles supported on Nb₂O₅-doped activated carbon (AC) were prepared via wet incipient impregnation with PdCl₂ followed by reduction with NaBH₄. The dispersed niobia plays a bifunctional role in the catalytic process: stabilizing Pd nanoparticles and acting as an acidic co-catalyst. This synergistic effect between niobia and Pd leads to an unprecedented high activity of supported Pd catalysts in EL hydrogenation. The synergy is correlated with both the niobia loading and calcination temperature, with 10 wt% Nb₂O₅ calcined at 500 °C showing the best performance (EL conversion of 87% and GVL selectivity of 97%) under mild reaction conditions (100 °C and 0.5 MPa H₂).