Regulation of Reactive Oxygen Species with In Situ Preparation of Flower-like Ce/Zr Mixed Oxides Coupling VPO Catalyst for Enhancing Aldol Condensation

To tackle carbon deposition on the surface of vanadium phosphorus oxide (VPO) catalysts during acrylic acid synthesis via aldol condensation of acetic acid (HAc) and formaldehyde (HCHO), a novel catalytic system featuring VPO supported on CexZr1–xO2 (x = 0.4–0.8) solid solutions was developed to enhance oxygen mobility via oxygen vacancy engineering for suppressing coke formation. Structural analysis revealed that the flower-like morphology increased active site exposure, while EPR/XPS confirmed oxygen vacancies promoted oxygen migration and stabilized V4+ species. Response surface methodology-optimized 60% VPO/Ce0.6Zr0.4O2 achieved 82.12% acrylic acid yield under mild conditions, maintaining 81% yield over 50 h by leveraging active oxygen (O–/O2–) migration to prevent coking. Kinetic studies demonstrated the synergistic effects of oxygen vacancies, lattice oxygen, Ce3+, and V4+ reduced α-H activation energy to 34.063 kJ/mol, enhancing reactant adsorption. This work provides a structural engineering approach for oxygen-mobile catalysts in cross-aldol condensation systems.