Synergistic Effects of Pt-embedded, MIL-53-derived Catalysts (Pt@Al2O3) and NaBH4 for Water-mediated Hydrogenolysis of Biomass-derived Furfural to 1,5-Pentanediol at Near-ambient Temperature

Abstract We demonstrate an effective and selective conversion of biomass-derived furfural (FAL) to 1,5-pentanediol with high yields through a water-mediated hydrogenolysis process under mild reaction conditions (45 °C, aqueous media). A novel alumina-supported platinum catalyst (Pt@Al2O3) with high-loading and uniform distribution of Pt nanoparticles is prepared through in situ synthesis of Pt-embedded metal-organic frameworks (i.e., MIL-53(Al)-NH2). As a typical example, a high yield of 75.2% 1,5-pentanediol (1,5-PD) can be achieved from FAL conversion. A possible reaction mechanism is proposed based on the experimental and computational findings, including XPS analysis, kinetic studies, acidity measurements, and density functional theory (DFT) calculations. The high effectiveness of the proposed system is attributed to (1) the strong metal support interaction (SMSI) between Pt and penta-coordination aluminum, and (2) the synergistic effect of Bronsted acidic alumina support and the presence of NaBO2. Sodium borohydride (NaBH4) acts as both a hydrogen donor and a precursor for sodium metaborate (NaBO2), which results in an exclusive FAL to 1,5-PD (i.e., no 1,2-pentanediol) by regulating the water-mediated hydrogenolysis pathway as revealed by experiments and DFT calculations. The reaction strategy proposed in this study has also manifested remarkable versatility for a wide range of furan derivatives.