Palladium–Rhenium Catalysts for Selective Hydrogenation of Furfural: Evidence for an Optimum Surface Composition

Abstract

Bimetallic catalysts comprising a platinum-group metal (e.g., Pt, Pd, Ru) and rhenium (Re) have important applications in petroleum refining, industrial chemicals production, and biomass conversion. In this work, a series of PdRe/Al2O3 catalysts was investigated for selective hydrogenation of furfural to furfuryl alcohol (FAL) at 150 °C and 1 atm in a differential reactor. The results demonstrate that PdRe/Al2O3 catalysts have greater FAL selectivity and activity than Pd/Al2O3 catalysts. Over the bimetallic catalysts, decreased furan production is accompanied by a marked increase in hydrogenation activity. PdRe 1:1 catalysts prepared using [Pd(NH3)4](NO3)2 are significantly more active than catalysts prepared using Pd(NO3)2. PdRe 1:2 catalysts are more selective to FAL but less active than 1:1 catalysts prepared using the same precursors. The superior activity of PdRe/Al2O3 catalysts for selective hydrogenation of furfural is inferred to result from Re surface modification of Pd nanoparticles—disrupting P...