Construction of UiO-67 supported heteropolyacid with enhanced catalytic activity for biodiesel production via esterification

Metal–organic frameworks (MOFs) are recognized as a pivotal role in catalysis. Through control of MOFs synthesis conditions (e.g., time, temperature, ligand content, and agent type), offering the potential for improving catalytic performance and broadening application prospects of porous MOF-based composites. Based on this rationale, a series of HPW@UiO-67 catalysts with different organic ligand concentrations was fabricated via a simple one-pot hydrothermal method and evaluated for esterification activity. Characterization techniques such as FTIR, XRD, N2 physisorption, SEM, EDX, TG, NH3-TPD, Py-FTIR, and XPS were systematically analyzed to determine the physicochemical properties of the synthesized composite catalysts. These analyses confirmed that the concentration of H2bpdc ligands significantly influenced the porous characteristics, surface morphology, and catalytic performance of the composites. Among the catalysts tested, the HPW@UiO-67–1 catalyst with the addition of 2 molar quality of H2bpdc exhibited superior activity in the production of biodiesel from oleic acid (OA) esterification than that of other synthesized catalysts, achieving a 93.9% conversion, which was primarily attributed to their mesopore surface area (465.8 m2/g), available multi-scale pore morphology structure, high acidity capacity (0.95 mmol/g), and abundant Brønsted and Lewis acidic sites. The optimal catalyst of HPW@UiO-67–1 exhibited good stability, and the cyclic experiments showed that the composite catalyst retained over 80% of its activity after four consecutive times. This work validated the synthesis strategic design of porous MOF-based hybrid materials for sustainable and efficient biofuels production.