Labile oxygen-driven catalytic ozonation via surface peroxide pathway for efficient wastewater treatment.

[Display omitted] • Labile oxygen (O lab) is generated in mullite by the introduction of Al-O 4. • O lab activates ozone via an unusual surface peroxide pathway to generate O lab -O*. • Atrazine can be efficiently degraded by catalytic ozonation over Mullite-O lab. • Mullite-O lab is promising for future non-biodegradable wastewater treatment. The aluminosilicate-based heterogeneous catalysts hold great promise for industrial catalytic ozonation; however, the lack of exploration into novel active sites and mechanism studies has impeded their development. In this work, we demonstrate that labile oxygen (O lab) can be generated in mullite (mullite-O lab) by the introduction of extra Al-O 4 tetrahedral units. In our experiments, mullite-O lab exhibits excellent performance in terms of catalytic ozone activation, with a degradation rate of 87.4 % within 15 min for nonbiodegradable atrazine, corresponding to a high quasi-first-order rate constant (k , 0.112 min−1), while the degradation constant is close to 0 for mullite without O lab. Operando Raman and density functional theory (DFT) simulations further reveal that O lab activates ozone via a novel surface peroxide pathway to generate surface O lab -O* species with a high oxidizing ability. The mullite-O lab is stable with an average Al3+ leaching of 0.339 ppm during cycling, meeting the effluent discharge standard of the total Al. Moreover, we achieve the kilogram synthesis of mullite-O lab , which shows promising activity in the catalytic ozonation of acrylic fiber wastewater, with the chemical oxygen demand (COD) and total organic carbon (TOC) removal rates of 46.0 %±4.8 % and 24.9 %±2.8 % for 5 cycles. This work is the first to demonstrate the role of O lab in ozone activation and provides an advanced mullite-O lab catalyst for future nonbiodegradable wastewater treatment. [ABSTRACT FROM AUTHOR]