Fenton-like Catalytic Removal of Organic Pollutants in Water by Framework Cu in Cu-Al2O3

Abstract

To address the problem of low activity for Fe-based Fenton-like catalysts at neutral pH, Cu-Al2O3 Fenton-like catalyst was prepared by a simple co-precipitation method. The samples were characterized by means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and diffuse reflectance UV-vis spectra (UV-vis DRS). The results showed that both Cu2+ and Cu+mainly existed in the bulk framework of Al2O3 for Cu-Al2O3 with appropriate Cu doping (lower than 4.77% Cu), forming the bond of Al-O-Cu, while excessive Cu doping in Al2O3 (e. g. 7.58% Cu) could result in the occurrence of extraframework Cu species. The Fenton-like catalytic performance of the prepared samples was evaluated by the degradation of 2-chlorophenol (2-CP) and Rhodamine B (RhB). The results showed that the catalyst with framework Cu species had high catalytic activity and stability for the degradation of 2-CP and RhB. After reaction for 2 h, the degradation rate of 2-CP reached up to 54% over Cu-Al2O3(4.77% Cu) in the presence of H2O2, the corresponding TOC removal reached 49%, and the Cu release concentration was only 0.0255 mg·L-1. However, the existence of extraframework Cu in Al2O3 would lead to the reduction of the catalytic performance. ESR analysis showed that·OH and HO2-/O2-· were the primary active species.