Efficient hydrogenation of concentrated aqueous furfural solutions into furfuryl alcohol under ambient conditions in presence of PtCo bimetallic catalyst

Abstract

Furfural (FAL), a major biomass-derived chemical, can be hydrogenated to yield the industrially important platform chemical, furfuryl alcohol (FOL). Although heterogeneous catalyst-based methods are known to yield FOL from dilute solutions of FAL, they mainly operate at high temperatures and/or high pressures of hydrogen and in the presence of organic solvents. In this work, we employ bimetallic PtCo/C catalysts with varying metal concentrations to achieve the maximum possible FOL yield (100%) at 35 °C under 0.1 MPa H₂ in water. With concentrated FAL (40 wt%) at 50 °C and under 1 MPa H₂ pressure, 86% yield of FOL was observed. Moreover, efficient catalyst recycling was observed over at least four runs with marginal loss in activity due to handling error and isolation of FOL in pure form confirmed by NMR and HPLC. Characterization of catalysts with several physico-chemical techniques (XRD, TEM, XPS, ICP, TPR) reveals the presence of electron-rich Pt and ionic Co species in proximity with each other and these work synergistically to facilitate maximum possible yield of FOL under ambient conditions and in water medium.