Preparation Of MIL-101(Fe)-based Composite And The Derivativeson:Investigation Of Catalytic Performance

MIL-101(Fe)of Metal-Organic Frameworks(MOFs),has the characteristics of large pores,high surface area,and large number of metal sites.The advantages make MIL-101(Fe)suitable for heterogeneous catalysis.In this paper,the preparation and catalytic performance of MIL-101(Fe)-based composites and derivatives were investigated.The main research contents are as follows:(1)Based on a simple hydrothermal method,the preparation of MIL-101(Fe)was optimized by changing the ratio of raw materials,and MIL-101(Fe)/SiO₂ was further prepared.At the same time,the catalytic performance of reduction of p-nitrophenol was investigated.The research found that compared with MIL-101(Fe),the catalytic activity of MIL-101(Fe)/SiO₂ was significantly improved due to the interfacial effect.The interface components can improve the free energy of solid interface and change the electron motion transfer mode of the interface.In addition,the catalytic stability of MIL-101(Fe)/SiO₂greatly improved in alkaline environment.It can be concluded that catalytic reduction of p-nitrophenol can simultaneously produce hydrogen according to the experimental phenomenon.The catalytic reduction of p-nitrophenol by MIL-101(Fe)-based composite for simultaneous hydrogen production and the reaction mechanism were further investigated.(2)MIL-101(Fe)and MIL-101(Fe)/SiO₂ were respectively converted into Fe₂O₃ and Fe₂O₃-SiO₂ materials by calcination.According to different preparation order,using impregnation-reduction method,hydrothermal method and improved Storm method,(Cu/Fe₂O₃)@SiO₂,(Cu/SiO₂)@Fe₂O₃ and Cu/(Fe₂O₃-SiO₂)were synthesized,and then applied in photocatalytic reduction of p-nitrophenol and degradation of ciprofloxacin and ibuprofen.The results show that the photocatalytic activity of Cu/(Fe₂O₃-SiO₂)is the best,and as the main active component,Cu can be exposed to the surface of the ternary Fe₂O₃catalyst and interact with different oxide supports respectively to achieve the best catalytic effect.Indicated that different combination sequence of each component of the ternary catalyst plays a significant role on the catalytic activity of the catalyst.Furhermore,the possible photocatalytic reaction mechanism of Cu/(Fe₂O₃-SiO₂)was proposed.(3)The impregnation-reduction method is used to load Au and Cu on different supports,then the composite materials were calcined for the reduction of p-nitrophenol and photocatalytic reactions.The results show that the metal-support effect between Cu and ZSM-5 is better than that of Au.Cu particles are smaller,with little change of particle size before and after calcination,and the catalytic activity of Cu/ZSM-5 is better.The catalyst with ZSM-5 as the carrier has the most stable catalytic performance under the effect of calcination.Thus,(Au Cu)/ZSM-5 was prepared by a similar method for photocatalytic reaction.It is found that(Au-Cu)/ZSM-5 has a small particle size and size change is not obvious after calcination.There is an interaction between Au and Cu at the same time.The carrier lifetime of(Au-Cu)/ZSM-5 is prolonged and the photocatalytic activity is further improved.The reaction mechanism of(Au-Cu)/ZSM-5 was finally proposed.