A Tunable and Universal Catalyst for Efficient One-Pot Conversion of Xylose to γ-Valerolactone

The one-pot synthesis of γ-valerolactone (GVL) from xylose is pivotal for sustainable biofuel and fine chemical production. This study introduces a novel catalyst, Hf-LS-Beta, which is tailored for efficient xylose conversion to GVL, subsequently applied in a tandem process for wheat straw pre-hydrolysate catalysis. The catalyst features dispersed Lewis acid active sites formed through Hf and lignosulfonate sodium (LS) coordination within the Beta porous structure, enhancing accessibility. Both the structure and acidic properties of the catalyst were tunable by varying precursor dosages, with optimal performance achieved at a total Lewis acid content of 118-128 μmol/g and a specific surface area of 171-186 m²/g. Under optimized conditions, the Hf (1.5)-LS-Beta (0.4) catalyst delivered the highest GVL yield of 45.71% from xylose and maintained high stability over five cycles. Furthermore, a GVL yield of 29.37% was attained from xylose-rich hydrolysate from wheat straw. This catalyst achieves record-high xylose conversion in isopropanol, efficiently promoting cascade reactions involving dehydration, hydrogenation, ring-opening, and lactonization for GVL formation. Substrate versatility was also demonstrated with the successful conversion of glucose and arabinose, indicating the strong potential for integrated two-step GVL production from lignocellulosic biomass.