Research On Supported Nanogold Catalysts Carried By Confined-structure

In recent years,gold nanoparticles controlled synthesis of various size and shape of gold nanoparticles has been initially achieved.At present,the research on the application of gold nanoparticles is becoming hot.With the long-term experiments,researchers found that different size and shape of gold nanoparticles will exhibit different performance in various types of applications.According to the characteristics of these gold nanoparticles with different dimensions and morphology,gold nanoparticles are widely used in various reaction,and develop its vast potential for the maximize benefits.Under this background,this subject focused on exploring the catalytic property on cracking reaction at high temperature.First,catalyst supported spherical gold nanoparticles are prepared by two different methods.In this paper,ZSM-5 was ued as carrier.Through effect comparison,we obtained the advantages loading method——The direct loading method.And then,catalyst supported non-spherical gold nanoparticles which have a lower yield are prepared by direct loading method.The result showed that the direct loading method had a good performance in loading gold nanoparticles with low yield.Taking CO oxidation as an example,the catalytic mechanism of catalysts supported gold nanoparticles were analyzed.Besides,the different catalytic effects of gold nanoparticles with different size and morphologies were also discussed.After calcination at high temperature,the gold nanoparticles were characterized by TEM.We found a problem of these supported catalyst in practical application.To solve this problem,this paper synthesized a kind of high temperature resistance confined-structure,and explored the optimal experimental conditions for its preparation.Subsequently,we characterized and analysed their surface structure by SEM,BET,XRD.It was found that the pore size distribution is 23~75nm and the effective size range of gold nanoparticles is 0~100nm.This means that the pore size distribution is meaning.At last,this paper supported the gold nanoparticles with different sizes on this confined-structure and conducted a high temperature resist experiments.This kind of catalyst exhibit a good high temperature resistance.This is because the path of gold nanoparticle agglomeration is interrupted by the confined-structure.As a result,a new method of preventing agglomerating of gold nanoparticles at high temperature in this case is achieved.It is of great research value.