Selective hydrogenation of succinic acid to gamma-butyrolactone with PVP-capped CuPd catalysts†
Abstract
Selective hydrogenation of succinic acid (SA) is not an easy task especially toward γ-butyrolactone (GBL) which readily undergoes further hydrogenation. Herein, poly(N-vinyl-2-pyrrolidone)-capped CuPd catalysts have been studied for the production of highly selective GBL from SA. The optimal catalyst not only exhibited remarkable activity and stability but also preserved its efficiency even at a mild hydrogen pressure of 1 MPa and long recycling runs. The presence of PVP is proposed to play a key role in maintaining high GBL selectivity under various conditions. Although a strong Cu–Pd interaction due to alloying is supposed to enhance substrate adsorption, GBL production could only be maximized if the CuPd alloy nanoparticles were enriched with Pd sites which are supposed to enhance the hydrogen activation.