Coupling Cu+ species and acid-base sites for boosting synergetic hydrogenolysis of glycerol to 1,2-propanediol

Copper-based catalysts are widely studied for glycerol hydrogenolysis due to their high 1,2-propanediol (1,2-PDO) selectivity. However, their performance is fundamentally limited by the low hydrogenation activity of metal copper and the unbalanced distribution of acid-base sites. Herein, we designed a MgO-coordinated Cu x /Mg y -Al 2 O 3 catalyst through lattice-selective doping, where Mg 2+ incorporation generates interfacial Mg-O-Al acidic sites while surface MgO clusters provided tunable basicity. The optimized Cu 0.3 /Mg 0.1 -Al 2 O 3 catalyst achieves complete glycerol conversion with 94.2% 1,2-PDO selectivity at 250 °C/3.5 MPa H 2 , surpassing conventional Cu-based catalysts. Through In-situ diffuse reflectance infrared Fourier transformations spectroscopy (DRIFTS) analysis combined with CO 2 /NH 3 -TPD measurements reveal that Mg doping stabilizes metastable Cu + species and establishes an adjustable acid-base distribution, crucial for selective C O cleavage. Mechanistic analysis identifies a sequential dehydration-hydrogenation pathway, where the synergistic interaction between Cu + active centers and precisely tuned acid-base dual sites promotes intermediate transformation kinetics, and effectively suppresses undesired side reactions through spatial confinement effects. This work establishes a design principle for multifunctional catalysts in biomass upgrading.