Preparation And Properties Of Highly Stable Noble Metal Nanocomposites

Due to the small size and high specific surface area,metal nanoparticles are of great value in catalysis,energy,medicine and other applications.However,the metal nanoparticles are sintered in practical applications,causing the particles to be dispersed unevenly and corresponding characteristics losing.Therefore,controlling the stability of metal particles is very important for application of the materials.Metal nanoparticles are often loaded on support to make them dispersed evenly and stable.Metal oxides are widely used as support.The hollow structure of metal oxides are used as great supports to load metal nanoparticles.It can not only stabilize the dispersed nanoparticles,but also facilitate the transfer of the reactants.The interaction between the metal nanoparticles and the supports takes special properties for materials.Therefore,the loaded hollow sphere nanomaterials have vital research and application value.In order to realize the good dispersion and stability of the metal nanoparticles,there are two different synthetic methods to prepare metal/metal oxide materials.They can make materials have good stability under high temperature conditions.（1）Nanomaterials such as Au/TiO₂,Pd/ZrO₂,Pt/ZrO₂ and Au/CeTiO₂ were prepared by the process route of urea formaldehyde resin polymer template method.The structure of hollow spheres was well regulated,and they were evenly distributed on the support.The agglomeration of the materials were reduced.The test results of CO and CH₄ catalytic oxidation showed that they have high catalytic activity,cycling performance and good stability.（2）Through the use of resorcinol formaldehyde resin polymer template method,TiO₂hollow metal oxide was prepared.On one hand,the Pt/TiO₂ with smaller and better dispersibility was obtained by loading Pt nanoparticles.This catalytic materials have high activity,cycling property and stability in CO oxidation reaction.On the other hand,the hollow TiO₂ was mixed with LiOH·H₂O to prepare electrode material Li₄Ti₅O₁₂ for lithium ion battery test,and good electrode materials performance was achieved.The preparation of the metal oxides ZrO₂ and CeTiO₂ has been realized by the same synthetic route,indicating the universality of the resorcinol formaldehyde resin polymer template method.