Mesoporous Cu-doped gamma-Al2O3 (gamma-Cu-Al2O3) was prepared via an evaporation-induced self-assembly process, in which Cu+/2+ was co-incorporated into mesoporous gamma-Al2O3 by chemical bonding of Al-O-Cu. The catalyst was found to be highly effective and stable for the degradation and mineralization of aromatic pollutants, as demonstrated with bisphenol A, 2,4-dichlorophenoxyacetic acid, ibuprofen, diphenhydramine, and phenytoin in the presence of H2O2 under neutral pH conditions. In addition, the high utilization efficiency of H2O2 was maintained at approximately 90 prior to the disappearance of the initial aromatic pollutants. On the basis of all of the characterization results, the pollutant degradation processes predominantly occurred on the surface of the catalyst due to the formation of sigma-Cu-ligand complexes between the phenolic OH group and the surface Cu. In the reaction system, in addition to the unselective oxidation by (OH)-O-center dot, H2O2 directly attacked the sigma-Cu2+-complexes aromatic ring with the phenolic OH group, which resulted in the formation of (OH)-O-center dot and HO-adduct radicals that were oxidized to hydroxylation products by reduction of Cu2+ in the sigma-Cu2+ complexes to Cu+. The process prevented Cu2+ from oxidizing H2O2 to form HO2 center dot/O-2(center dot-) or O-2, and enhanced the Cu+/Cu2+ cycle, the formation of (OH)-O-center dot, and the utilization efficiency of H2O2. Therefore, an extraordinarily high degradation and mineralization of the aromatic pollutants was observed.
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