The Development Of Copper Based Heterogeneous Fenton-like Catalysis And The Research For Organic Pollutant Degradation

Heterogeneous Fenton-like reactions for degradation of organic pollutants have attracted worldwide attention due to its high performance,simplicity and environmental friendly.However,poor activity under neutral condition,poor stability of the catalyst and low utilization efficiency of H2O2 are still the issues to be solved in heterogeneous Fenton-like reactions.Given these problems,we try to explore a catalyst which has excellent activity and stability for the degradation organic pollutants.The work and results are summarized as follows:In the first part,Cu-doped LaAlO3 perovskite(LaA1-xCuxO3)was synthesized via a sol-gel process for the oxidative degradation of persistent organic compounds.By the analysis of element mapping,X-ray diffraction,X-ray photoelectron spectroscopy,Raman spectra and the extended X-ray absorption fine structure,Cu was incorporated into the structure of sphere-like LaAlO3 with La/Al-O-Cu.The LaAl0.95Cu0.05O3 catalyst showed excellent activity and stability for the degradation and mineralization of various organic pollutants through heterogeneous Fenton-like reactions at the range of pH 5.0-9.0.The results of ESR and active species trapping experiments indicated that the high performance of LaAl0.95Cu0.05O3 mainly contributed to the generated amount of HO· radicals was nearly twice as that of the reacted H2O2 in the reaction.Combining with in-situ Raman analysis and the XPS results of LaAl0.95Cu0.05O3 before and after reaction,H2O2 was predominantly reduced to HO· on the electron-rich Cu center,and H2O2/H2O can be dissociated on oxygen vacancies(OVs)to enhance formation of HO-on the surface of LaAl0.95Cu0.05O3.This efficient material can potentially be used as a promising catalyst for the efficient degradation of organic pollutants in environmental pollution cleanup.In order to increase the active sites of catalyst,Cu-Al/KIT-6 catalyst was successfully synthesized by ultrasonication as impregnation method for bisphenol A(BPA)degradation.The catalyst was characterized by nitrogen adsorption/desorption isotherms and it shown great specific surface area.Cu-Al/KIT-6 performed excellent activity and stability for the degradation and mineralization of BPA through heterogeneous Fenton-like reactions.In addition,the results of DMPO spin-trap ESR and the BPA degradation experiments under different atmosphere indicated that O2 can interact with Cu-Al/KIT-6 that play an essential electron acceptor to trigger the decomposition of H2O2 at the beginning of reaction.Meanwhile,the generation of reactive oxygen species(HO· and O2·-radicals)was enhanced bubbled with O2 during the reaction.These findings will extend the scope of Fenton catalysts via surface engineering and consolidate the fundamental theories of Fenton reactions for wide environmental applications.