Defect-Engineered MOF-801 With Enhanced Lewis Acidity for Efficient Transfer Hydrogenation of Furfural to Furfuryl Alcohol

The catalytic transfer hydrogenation (CTH) of furfural into furfuryl alcohol offers a promising route for the valorization of lignocellulosic biomass using liquid hydrogen donors instead of high-pressure H 2 . In this work, a defect-engineered MOF-801 catalyst with abundant Lewis acid sites was synthesized through a formic acid-regulated hydrothermal approach. Competitive coordination between formic acid and fumaric acid favors the nucleation and growth of MOF-801, and enhances the Lewis acidity of the catalyst. Characterization by FT-IR, XRD, SEM, and pyridine-IR confirmed the successful formation of MOF-801 with dominant Lewis acid centers. Using isopropanol as the hydrogen donor, the optimized reaction conditions (130°C, 2 h, 1.0 MPa N 2 ) achieved 99.5% furfural conversion and 94.4% furfuryl alcohol yield. Kinetic analysis demonstrated a first-order reaction with an apparent activation energy of 41.3 kJ·mol − 1 . The catalyst showed excellent recyclability and retained its crystallinity after five consecutive cycles. This study provides a simple and efficient method for constructing Lewis acidic MOFs with coordination unsaturated metal sites for biomass-derived CTH reactions, supporting an upgrading and transformation of platform molecules under hydrogen-free conditions. Graphical A defect-engineered MOF-801 catalyst with abundant Lewis acid sites is synthesized via formic acid modulation. The unsaturated Zr 4 + centers effectively activate both furfural and isopropanol, enabling efficient catalytic transfer hydrogenation to furfuryl alcohol under mild, hydrogen-free conditions with excellent recyclability.