Study On The Preparation And Catalytic Performance Of Transition Bimetal Oxides

Fenton-like oxidation is an advanced oxidation processes（AOPs）for the degradation of organic pollutants.To promote the degradation of organic pollutants,developing catalysts with high efficiency and high stability is imperative for pratical application.However,the catalysts suffer from some problems including insufficient active sites and slow regeneration of low-valent metals,which greatly limit the degradation efficiency of pollutants.transition bimetal oxides,a class of efficient Fenton-like catalysts,has aroused much attentions due to their high catalytic performance and stability.In this work,employing transition bimetal oxides to drive Fenton-like reaction were systemically investigated.It can be found that the transition bimetal oxides can provide enough active sites in the catalytic process to enhance the regeneration of low-valent metal and the decomposition of hydrogen peroxide through synergistic effect,which are conducive to improving the catalytic performance.The specific research contents are listed as follows:（1）The low formation efficiency of hydroxyl radical（^·OH）in AOPs restricts the degradation efficiency.In this work,the spinel type cobalt acid manganese（Mn Co₂O₄）with flower morphology was fabricated through a co-precipitation method.Compared with Co₃O₄ and Mn₂O₃,Mn Co₂O₄（CM3,molar ratio of Co:Mn=3）has more Lewis acid sites to produce more^·OH.Thus,the obtained CM3 shows a higher ciprofloxacin（CIP）degradation ratio（81%）than that of Co₃O₄ and Mn₂O₃.In addition,density functional theory（DFT）is used to calculate the free energy for activation of H₂O₂ by Mn Co₂O₄,Co₃O₄ and Mn₂O₃.The results show that Mn Co₂O₄is more favorable for the rupture of O–O bond to generate^·OH.This work offers effective catalysts for CIP decomposition and provides feasible route for treating practical environmental problems.（2）A Cu-Mn bimetallic oxide catalyst(Cu_0.451Mn_0.549O₂)with mixed valence states of Mn（III/IV）and Cu（II/I）was prepared by co-precipitation method.In the degradation process of CIP,the electrons of Cu_0.451Mn_0.549O₂catalyst spontaneously transfer from Cu⁺to Mn³⁺,accelerating the regeneration of Mn²⁺.It promotes the generation of^·OH in the decomposition process of H₂O₂ and improves the degradation rate of CIP（90%）.Compared with Mn O_x,Cu_0.451Mn_0.549O₂ exhibits better conductivity and stronger redox capacity.The catalyst can deliver high catalytic activity in a wide p H range,which shows a good prospect for practical application.