Prepation Of Iron-copper Bimetal Doped Mesoporous ?-Al₂O₃?Fe/Cu-?-Al₂O₃?Fenton-like Catalysts And Its Removal Study Of 4-chlorophenol

Heterogeneous Fenton-like catalytic method,as an effective advanced oxidation processes?AOPs?for eliminating recalcitrant organic pollutants in water,has the advantages of mild reaction conditions,simple equipment and low-cost,compared to the other AOPs,such as photo-cataytic technology and ozonation technology.However,some disadvantages of heterogeneous Fenton-like catalytic technologe,including narrow pH response range,poor catalytic activity and low H₂O₂ utilization efficiency?above the 100-fold stoichiometric amount used?,hinder its industrial application.Therefore,it is crucial importance to develop a novel heterogeneous Fenton-like catalyst with high catalytic activity and high H₂O₂utilization efficiency under neutral condition.In this paper,iron-copper bimetal supported on mesoporous?-Al₂O₃ with different Fe/Cu ratios?Fe/Cu-?-Al₂O₃?were prepared via a modified evaporation-induced self-assembly method and employed to degrade 4-CP in Fenton-like process.Main research results of this paper were shown as follow:?1?SEM,BET,XRD,UV-vis DRS and XPS were conducted to confirm the co-doping of Fe²⁺/Fe³⁺and Cu⁺/Cu²⁺into the octahedral site of the spinel lattice of?-Al₂O₃ through the bonds of Al-O-Fe and Al-O-Cu.Additionally,the doping iron/copper did not lead to the collapse of mesoporous structure,and with the iron and copper co-doped in?-Al₂O₃,a large number of oxygen vacancies?V₀?were produced.?2?The 1Fe3Cu-?-Al₂O₃ with a Fe/Cu mass ratio of 1:3 exhibited the best activity on Fenton-like degradation of 4-CP.With the addition of 1Fe3Cu-?-Al₂O₃(2.0 g L^-1)and H₂O₂?30mM?,the utilization efficiency of H₂O₂ was as high as 86.0%after the almost disappearance of4-CP?i.e.,99.7%of 0.78 mM 4-CP?at 240 min and pH 7.0,additionally,approximately 92.0%of dechloridation and 81.6%of TOC removal efficiency were obtained in this Fenton-like process.The catalyst showed high catalytic performance and high H₂O₂ utilization efficiency under neutral condition.Moreover,1Fe3Cu-?-Al₂O₃ catalyst was stable and showed a good reusability for the Fenton-like reaction.?3?During the heterogeneous Fenton-like reaction of 4-CP,the Fe and Cu species of1Fe3Cu-?-Al₂O₃ were the active sites for activation of H₂O₂ on 1Fe3Cu-?-Al₂O₃ surface to produce·OH radicals.Two main mechanisms include the synergistic effects of Fe and Cu involving the production of a large number of V₀ and the thermodynamically favorable process of the reduction of Fe³⁺to Fe²⁺by Cu⁺,and the the formation of?-Cu²⁺-Al₂O₃ complexes,both of them could avoid H₂O₂ as an electron donor and facilitate the recycles of Cu⁺/Cu²⁺and Fe²⁺/Fe³⁺followed by the increase in the generation of·OH,which led to more effective catalytic activity and higher utilization efficiency of H₂O₂ in Fenton-like process.?4?The result of GC-MS analysis indicated that the 4-CP degradation with 1Fe3Cu-?-Al₂O₃/H₂O₂ was firstly degraded into benzoquinone,hydroquinone,4-chlororesorcinol,4-chlorocatechol and other intermediates,with the·OH radicals continually attacking,some small molecule acids were produced,and finally mineralized into carbon dioxide and water to realize the removal of 4-CP.