Application Of Organic/inorganic Nano-composite Microspheres In The Catalytic Reaction And Phase Change Enery Storage

In recent years,organic/inorganic nanocomposite microspheres due to the unique and comprehensive performance,have attracted much attention and obtain very important scientific and industrial value because of applications in the catalytic,energy storage and conversion,sensors,optoelectronic devices,nano-biotechnology and gas selection through the membrane.The two components of organic/inorganic composite nanospheres are mixed at nanoscale,and the effective recombination between nanomaterials can not only realize the integration of functionalities between materials,but also may produce the special properties of nanomaterials that are not possessed before recombination nature.In this paper,a series of organic/inorganic composite nanospheres with special morphology and novel structure were prepared from the control synthesis of organic/inorganic composite nanospheres.Their applications in the field of catalysis and energy storage were explored and studied.And the structure-activity relationship between material structure and properties was studied.It provided theoretical and experimental basis for structural design,performance control and practical application of organic/inorganic composite nanospheres in related fields.The research of this thesis includes the design and preparation of three kinds of different structures and compositions of organic-inorganic nanocomposite microspheres applied in the catalysis and energy storage,the main conclusions are:(1)With the magnetic nanoparticles(Cu-CuFe2O4)as the core,along with the Cu(0)component of Cu-CuFe2O4 was in situ transformation to HKUST-1,the surface of Cu-CuFe2O4 was coated with HKUST-1 octahedral microporous crystals.Then,the Cu-CuFe2O4@HKUST-1 nanocomposite microspheres with core-shell structure were prepared.This method has overcome the shortcomings(harsh reaction conditions,long cycle and complex processing and other shortcomings)of the traditional method of layer and layer self-assembly to prepare the micro-nano particles@MOF s.When Cu-CuFe2O4@HKUST-1 nanocomposite microspheres were used in catalysts,the advantages of excellent structural properties(large specific surface area,uniform pore size distribution,controllable topology and adjustable pore size)of MOFs and the catalytic properties of Cu-CuFe2O4 nanoparticles are achieved.The catalyst can efficiently catalyze the oxidation of benzylic C-H bonds under the condition of molecular oxygen as the green oxygen source and under low temperature.In addition,Cu-CuFe2O4 magnetic core can achieve rapid separation and recovery of the catalyst;further,HKUST-1 shell with microporous structure can protect Cu-CuFe2O4,to avoid the loss of catalytic active components in the reaction.(2)With monodisperse polyvinylpyridine microspheres(P4VP)as supporter,along with unshared pair electrons of N atom of P4VP microspheres can coordinate with Fe3+ to realize the solid loading of the homogeneous ferric catalytic materials,then the novel heterogeneous iron catalyst was prepared.By controlling the degree of crosslinking of monodisperse polyvinylpyridine composite microspheres to realize the different ability to load iron ions,a series of different P4VPDVB2.5-40%-Fe(?)catalysts were obtained.The oxidation reaction of bis(4-fluorophenyl)methane was used as a probe reaction,the effect between different degree of crosslinking of the polymer and different content of iron ions in the supported catalysts was studied.The experimental results show that the catalyst P4VPDVB10%-Fe(?)exhibits the excellent catalytic performance when the content of the crosslinking agent(DVB)is 10%.The catalyst has good stability,and the catalytic material has good universality for the oxidation of benzyl substrate.In addition,the pyridine moiety of the synthesized catalyst is capable of acting as an organic base,thereby significantly reducing the amount of pyridine present in the system.(3)The mesoporous silica shell was coated on the outer layer by hydrothermal method using a sulfonated polystyrene microspheres(PS)as a core,then the PS@SiO2 composite microspheres were obtained.The mesoporous hollow SiO2 microspheres were obtained prepared by high temperature calcinations of PS@SiO2 composite microspheres.Using the mesoporous hollow SiO2 microspheres as supporter,the stearic acid(SA)was uniformly immobilized in the supporter by physical adsorption method,finally,SA/mesoporous hollow SiO2 microspheres composite phase change materials were prepared.The mesoporous hollow SiO2 microspheres consist of a mesoporous shell and a hollow cavity.The mesoporous shell with strong capillary force can absorb the stearic acid to the hollow cavity.The vast majority of the phase change material is present in the cavity,which is beneficial to the free crystallization of the molecular chains of the stearic acid,resulting in high energy storage efficiency of the shaped phase change material.The hydrogen bond between the SA and the mesoporous hollow Si02 microspheres and the capillary force of the pores play an important role in the formation of molten SA.The mesoporous hollow SiO2 microspheres have enhanced the thermal conductivity of SA,and the increase rate is 56%.The composite phase change material still retains good phase transition performance after 50 cycles.