Hydrogenation of furfural over Pd–Cu/Al2O3 catalysts. The role of interaction between palladium and copper on determining catalytic properties

This paper studies the effect of copper on the activity and selectivity of home-made supported palladium catalysts during liquid phase hydrogenation of furfural. Bimetallic Pd–Cu/Al2O3 catalysts containing 5 wt.% Pd and 1.5–6 wt.% Cu showed high activity. However, the incorporation of Cu limited the formation of tetrahydrofurfuryl alcohol in comparison to monometallic Pd/Al2O3 catalysts. Activating the catalysts at 300 °C in a hydrogen atmosphere led to the formation of Pd–Cu alloys, as confirmed by XRD, SIMS-ToF, SEM-EDS, FTIRS-CO and TPR-H2. The composition of the alloys depended on the amount of copper incorporated into the catalysts. The incorporation of copper can therefore be assumed to modify the catalytic properties of bimetallic Pd–Cu/Al2O3 systems used in the hydrogenation of furfural.