| ZrO2 is a catalyst carrier for heterogeneous reactions due to the acidic-basic surface,abundant oxygen vacancy,and weak hydrophilic character.ZrO2-based oxides are widely used in the heterogeneous reaction.Therefore,regulating the chemical composition,the specific surface area,the crystallinity,surface acid-base sites,micro-nano structure,and other properties of ZrO2 materials can effectively improve the number and types of active sites on the surface of materials and promote the diffusion of substances to enhance the catalytic performance.For this purpose,this thesis synthesized a series of ZrO2-based hybrid materials through the porous template,microfluidic,and electrospinning technology.The composite catalysts with excellent performance are further prepared using ZrO2-based hybrid materials as carriers,which realized the efficient catalysis of Fenton reaction and dehydration of fructose.The main results are as follow:(1)The mesoporous zirconia is prepared by the porous monolithic SiO2 as a hard template and triblock copolymer as a soft template.The contradiction between specific surface area and crystallinity of ZrO2 is effectively balanced by the synergistic effect of the dual template.The special surface area of ZrO2 can reach 277 m2 g-1.ZrO2 maintains the tetragonal phase at roo1 temperature.The solid acid is obtained after modifying the surface of materials by sulfuric acid.The solid acid performs excellent catalytic activity in biomass conversion and can efficiently catalyze the dehydration of fructose to produce 5-hydroxymethylfurfural.The yield of 5-HMF is 78%in 1h.(2)Hollow magnetic zirconia nanofibers are prepared based on coaxial electrospinning.The nanofibers have a uniform structure,with a diameter of 1 μm and a wall of 100 nm.The nanofibers have a larger special surface area due to the hollow structure.As the iron oxides loading on the surface by combining with Lewis acid sites,the heterogeneous catalysts show excellent performance for the Fenton reaction to degrade ultrahigh concentration organics.In the Fenton reaction,50 ppm methylene blue solution can be degraded by 99%in 5 min.The degradation rate of 300 ppm dye solution can reach 90%in 120 min.More importantly,after adding a magnetic component into fibers,the catalysts can be easily recycled and reused.After 5 cycles,degradation efficiency still maintains at 90%(3)The ZrO2-based hybrid metal oxide fibers are obtained by electrospinning assisted with microfluidic chips.The homogeneous mixing binary hybrid oxide fibers can be obtained.The sulfate ZrO2-SiO2 hybrid fibers show excellent catalytic performance in biomass conversion from fructose to 5-hydroxymethylfurfural via strengthening surface acidity.The space-time yield of 5-HMF is 3.82 g L-1 h-1.Utilizing the basicity on the surface of the ZrO2-MgO hybrid fiber,the Au nanoparticles are supported on the surface of the fiber,and the oxidation reaction from 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid can be carried out.The space-time yield of FDCA is 29.86 g L-1 h-1.The catalytic efficiency of the fiber can maintain at 95%after continuously using more than 100 hours.The continuous production from fructose to FDCA is realized.(4)ZrO2-based hybrid metal oxide fibers are ideal carriers to support ferric oxide,which are prepared based on the combination of electrospinning and microfluidic.The normalized K edge X-ray absorption near edge structure spectra show that iron oxide is highly dispersed on hybrid fibers’ surface.The dispersity of active ingredient profits from the chemical constitution on the surface of the hybrid fiber.Therefore,the fibers show excellent performance for the dehydration of the sewage in the Fenton reaction.The catalysts perform excellently in degrading ultra-high concentration dye and phenol solution.The degradation of 500 ppm methylene blue solution is 90%in 90 min by the iron-loaded ZrO2-SiO2 fibers. |
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