Efficient mineralization of phenol in high chloride solutions via Fenton reactions using γ-Cu2(OH)3Cl as a catalyst

γ-Cu 2 (OH) 3 Cl is used as a Fenton catalyst to mineralize phenol in high chloride solutions. The mineralization of phenol can be enhanced even at 15000 mg∙L –1 NaCl under ambient pH. In addition, other aromatic contaminants including bisphenol A , benzoic acid , 2-chlorophenol, salicylic acid and aniline can also be effectively mineralized under the high chloride concentration. However, reference catalysts including CuSO 4 , CuO and Cu 2 O are significantly depressed by chloride. The chloride resistance ability of γ-Cu 2 (OH) 3 Cl is proposed. First, σ-Cu-ligand complexes formed between Cu 2+ and phenolic hydroxyl can react with H 2 O 2 to promote the rapid reduction of Cu 2+ to Cu + , which are not hindered by chloride. Second, the self-redox property of γ-Cu 2 (OH) 3 Cl which initiates the electron transfer from H 2 O 2 to Cu 2+ to generate Cu + is improved by chloride. Third, the circumneutral pH could suppress HO• scavenging by chloride. The activation energies of phenol mineralization over γ-Cu 2 (OH) 3 Cl in chloride-free and high chloride solutions are 42.9 and 32.3 kJ∙mol –1 , respectively. Chloride does not change the phenol mineralization pathway but accelerates its degradation into small carboxylic acids.