Pt/Mg AlO bifunctional catalysts with various Mg/Al ratios for selective hydrogenation of furfural alcohol to 1,2-pentanediol

The selective production of valuable 1,2-pentanediol (1,2-PeD) by biomass-derived furfural alcohol (FFA) hydrogenation is challenging due to the diverse unsaturated groups and robust C5–O bond. Here, a series of Pt/MgxAlOy catalysts with tunable Mg/Al molar ratio were modified to adjust metal-support interactions and oxygen vacancy in promoting FFA hydrogenation in aqueous phase. Among them, Pt/Mg7AlO exhibited excellent catalytic performance, reaching almost complete conversion of FFA and the highest selectivity of 64.9% to 1,2-PeD. A combination study involving X-ray photoelectron spectroscopy (XPS), in situ CO diffuse reflectance Fourier transform infrared spectroscopy (CO-DRIFTS) and in situ FT-IR, confirms that the electrons-rich Pt0 species contribute to the significantly enhanced FFA hydrogenation via promoting C5–O bond cleavage. In-situ FT-IR experiments give direct evidence that the unique distorted adsorption mode of C4=C5–O groups in FFA induces high selectivity for targeted 1,2-PeD over Pt/Mg7AlO, while the parallel adsorption of furan ring is extremely suppressed. This study emphasizes the significance for optimizing defect sites of MgxAlOy in rationally tuning Pt surface states for selective hydrogenation of biomass-derived furan compounds.