<p>Heterogeneous catalytic ozonation can effectively degrade the contaminants in wastewater due to the strong oxidizing hydroxyl radicals (HO•) are produced in the catalytic ozonation. Although the porous ceramsite features a large specific surface area, good physical strength, and a stable chemical composition, it suffers poor stability and a low HO• generation efficiency. Herein, CuCe doped ceramsite (CuCe@Ceramsite) was successfully prepared by the wet impregnation, alkali precipitation and post-calcination method. Compared to the O₃ and single metal doped ceramsite/O₃ processes, a higher degradation and mineralization efficiency for the benzotriazole (BTA) oxidation in the CuCe@Ceramsite/O₃ process is obtained under optimal conditions, which could be attributed to the enhanced production of HO•. Numerous tests (i.e., electron paramagnetic resonance (EPR), radical quenching experiments) confirm that the oxidation of BTA is predominantly governed by O₃ and HO•, whereas O₂^•− and ¹O₂ play a minor role. Furthermore, the addition of SO₄²⁻, Cl⁻, NO₃⁻, and humic acid (HA) does not exert any discernible influence on the degradation of BTA in the CuCe@Ceramsite/O₃ process, whereas HCO₃⁻/CO₃²⁻ promotes the oxidation of BTA. Additionally, CuCe@Ceramsite demonstrates remarkable catalytic performance for BTA oxidation in recycling tests. As a result, CuCe@Ceramsite has the potential to remove refractory pollutants via the catalytic ozonation.</p> Graphical Abstract <p></p>