Efficient Hydrogenation of Glucose to Polyols over Hydrotalcite-Derived PtNi Alloy Catalyst under Mild Conditions

Polyols are important biomass-based building blocks for chemical production. In this work, a hydrotalcite-derived PtNi alloy catalyst (PtNi/HT) was prepared with high metal dispersion under microwave-assisted synthesis and employed for glucose hydrogenation, where 95.7% of glucose was converted with 90.1% selectivity into polyols at 393 K in water. The PtNi/HT was stable and could be recycled for at least five runs for glucose. Lower reaction temperatures (333-373 K) contributed to glucose hydrogenation to hexitols, while higher reaction temperatures (373-413 K) facilitated the C-C activation of glucose to generate more polyols with less carbon (C2-C4). The Ptδ-Niδ+ pair on PtNi/HT contributed to both H2 activation and adsorption of the aldehyde group in glucose hydrogenation. The basic support of PtNi/HT can efficiently catalyze the glucose isomerization and retro-aldol reaction in the aqueous phase. This study advocates a green approach for sustainable biorefinery of readily available glucose into value-added chemicals.