Bifunctional Al ³⁺ /Sulfonic Acid‐Modified UiO‐66‐NH ₂ for Efficient Glucose‐to‐HMF Conversion in Biphasic System

ABSTRACT The efficient catalytic conversion of glucose to 5‐hydroxymethylfurfural (HMF) is a key challenge in biomass valorization, requiring catalysts with both acidic sites and good stability to achieve high HMF yield and selectivity. Herein, sulfonic acid groups and Al 3+ were introduced to UiO‐66‐NH 2 for forming MOF‐based catalyst contained Brønsted acid and Lewis acid sites. A bifunctional solid acid catalyst Al/UiO‐66‐NH‐SO 3 H with dual acid sites was prepared by a grafting and loading strategy. The structure and properties of catalyst was analyzed by SEM, XPS, BET, XRD, TGA, and Py‐IR. In a 1,4‐dioxane/water biphasic system, high glucose conversion of 98.5% and HMF yield of 64.9% was obtained under the catalysis of Al/UiO‐66‐NH‐SO 3 H at 180°C within 100 min, outperforming most reported heterogeneous catalysts. This catalyst demonstrates excellent recyclability and the 89% activity retention after four cycles. This work provides a rational design strategy for multifunctional MOF catalysts in biomass conversion, offering a promising and sustainable pathway for the production of high‐value chemicals.