Catalytic ozonation of bisphenol A by Cu/Mn@γ-Al₂O₃: Performance evaluation and mechanism insight

Herein, an alumina-based bimetallic catalyst (Cu₁Mn₇@γ-Al₂O₃) was synthesized for bisphenol A (BPA) degradation in the catalytic ozonation process. The catalytic ozonation system could degrade 93.9% of BPA within 30 min under the conditions of pH = 7.0, 10 mg L^-1 O₃ concentration, and 24 g L^-1 catalyst dosage compared to ozone alone (21.0%). The enhanced BPA degradation efficiency was attributed to the abundant catalytic sites and synergistic effects of Cu and Mn. The results revealed that the synergistic interaction between Cu and Mn effectively accelerated the electron transfer process on the catalyst surface, thus promoting the generation of reactive oxygen species (ROS). Further studies indicated that the BPA degradation in Cu₁Mn₇@γ-Al₂O₃/O₃ system predominantly followed the ·OH and O₂^·- oxidation pathway. Based on the density functional theory (DFT) calculations and intermediates detected by LC-MS analysis, two pathways for BPA degradation in the Cu₁Mn₇@γ-Al₂O₃/O₃ system were proposed. The toxicity estimation illustrated that the toxicity of BPA and its byproducts was effectively reduced in the Cu₁Mn₇@γ-Al₂O₃/O₃ system. This work provides a new protocol for O₃ activation and pollutant elimination through a novel bimetallic catalyst during water purification.