Activation and stabilization of the Cu species via strong CuO-CeO2 interactions for enhanced decomposition of refractory aromatic organic pollutants in water.

[Display omitted] • Composite CuCeO x -A catalyst with strong CuO-CeO 2 interactions were prepared. • CuCeO x -A afforded a TOF that was 6.8 times that of CuO for TOC removal from 2-naphthol solution. • Cu leaching of CuCeO x -A was at lower level of 1.0 ± 0.2 mg/L than that of CuO (12.8 ± 1.9 mg/L) • CuO-CeO 2 interactions facilitated Cu+ regeneration by up-lifting the redox potential of Cu2+/Cu+. • The Cu species was stabilized in CuCeO x -A via the Cu–O-Ce bonds. The copper (Cu)-driven advanced oxidation process (AOP) represents one green and efficient technology for the removal of refractory aromatic organic pollutants from water. However, its application remained challenged by the sluggish regeneration of the active Cu+ species and the environmental risk induced by Cu leaching. Herein we reported a facile approach to the bimetallic composite CuCeO x -A catalyst with strong CuO-CeO 2 interactions ("A" referred to the acid-activation process). It enabled a TOC removal efficiency (δ%) of 92.4 % and a turnover frequency (TOF) of 1.57 min−1 for TOC removal from 100 mg/L 2-naphthol aqueous solution, outperforming the CuO (δ% = 82.9 % and TOF = 0.23 min−1) and most of the reported Cu-based catalysts. It was more active under neutral/weakly acidic conditions, and could keep high performances in a wide 2-NAP concentration window and in the presence of some impurity ions (PO 4 3-, NH 4 + or SiO 3 2-). Additionally, the Cu leaching of CuCeO x -A maintained at a much lower level of ∼ 1.0 ± 0.2 mg/L than that of CuO (∼12.8 ± 1.9 mg/L). Mechanistic studies demonstrated that the enhanced AOP performance and chemical stability of CuCeO x -A originated from the strong CuO-CeO 2 interactions, which facilitated the Cu+ regeneration by up-lifting the redox potential of Cu2+/Cu+ and stabilized Cu species via the Cu–O-Ce bonds. Further biological safety testing using chlorella cells as probe organism revealed that the CuCeO x -A-driven AOP was environmentally benign for aromatic organic pollutants removal. [ABSTRACT FROM AUTHOR]