Green Piezo‐Photocatalytic Oxidation of HMF to DFF Over Mn‐Doped Zr/Hf‐Based UiO‐66 Frameworks Under Mild Conditions

Developing energy‐efficient strategies for converting biomass‐derived platform chemicals remains critical for sustainable chemistry. Efficient conversion of biomass‐derived 5‐hydroxymethylfurfural (HMF) to high‐value 2,5‐diformylfuran (DFF) remains challenging due to energy‐intensive processes and poor selectivity. Here, we developed a novel Mn‐doped bimetallic UiO‐66(Zr/Hf)‐NH 2 piezoelectric photocatalyst via solvothermal synthesis. The optimal 3Mn/UZH0.5 catalyst (Zr/Hf = 1:1, 3.10 wt% Mn) achieves 81.3% HMF conversion and 68.9% DFF yield with 84.8% selectivity within 2 h, delivering high productivity (1377.8 μmol g –1 h –1 ) under mild conditions, while maintaining >75% selectivity over 5 cycles. Mechanistic studies reveal that ultrasound‐induced piezoelectric fields suppress electron–hole recombination, while Mn 3+ /Mn 4+ redox cycling and dominant reactive oxygen species (·O 2 – and 1 O 2 ) enable selective HMF oxidation. This work establishes a green catalytic platform using simultaneous solar/mechanical energy for biomass upgrading, advancing circular bioeconomy goals.