Surface acidity engineering of phosphate-modified ceria for photocatalytic SF6 degradation and cycling stability

Sulfur hexafluoride (SF 6 ) is a potent greenhouse gas widely used in electrical insulation due to its exceptional dielectric properties. Existing technologies are hampered by intractable issues such as prohibitive energy consumption and catalyst fluorination, making continuous operation difficult. Herein, we present a novel strategy leveraging synergistic Brønsted acid–oxygen vacancy (V o ) sites on a phosphoric-acid modified CeO 2 catalyst (PCe-90). This unique bifunctional design retains intrinsic V o of CeO 2 while introducing dense P–OH acid sites via a simple surface modification. Under 365 nm LED irradiation PCe-90 delivers 4.27 mL g −1 SF 6 mineralization within 24 h (8.5× pristine CeO 2 ). Crucially, PCe-90 demonstrates exceptional long-term robustness, maintaining undiminished activity over six cycles and 96 h of continuous operation without structural degradation. Mechanistically, P–OH protonates and polarizes the inert S–F bond, while V o injects electrons into the σ*(S–F) orbital to enable complete scission. This work establishes a synergistic catalytic mechanism and delivers a scalable, energy-efficient, and durable solution for practical SF 6 emission abatement.