Selective Conversion of Cellulose into Sugar Alcohols Catalyzed by Synergistic Brønsted–Lewis Acid Sites on a Zirconium Phosphate-Supported Ru Catalyst

High-value utilization of cellulosic biomass proves critical to advancing sustainable development and unlocking circular economy potential. This work reports a bifunctional zirconium phosphate (ZrP)-supported Ru catalyst (Ru/ZrP) for efficient cellulose-to-sugar alcohol conversion, delivering a 56.4% C6 sugar alcohol yield under reaction conditions of 200 °C and 3 MPa H2. The performance shows a 24-fold enhancement relative to Ru/ZrO2 (2.4% yield), with combined characterization and kinetic studies confirming that Brønsted–Lewis acid (P–OH/Zr4+) synergy governs the catalytic enhancement. Brønsted acid sites drive cellulose hydrolysis to glucose by accelerating β-1,4-glycosidic bond cleavage, while Lewis acid sites synergize with Ru sites to promote hydrogenation of glucose into sorbitol. Notably, the optimized Ru/ZrP1.4 catalyst also enabled effective disaccharide-to-sugar alcohol conversion, achieving a 54.3% C6 sugar alcohol yield using cellobiose as the substrate and maintaining stability over five cycles without any obvious deactivation. This work elucidates the critical roles of Brønsted–Lewis acid sites in mediating cellulose conversion, establishing a robust and efficient multifunctional Ru/ZrP catalyst for aqueous-phase biomass catalysis.