The Structural Properties Of Bimetallic Nanoparticles Au-Pt

In recent years the nanoscale bimetallic catalysts have been paid attention, because of their unique physical and chemical properties. It is found that widely used in energy, chemical industry, electromagnetic, mechanical, and other fields. In the future they will have a significant effect in the petroleum chemical industry, fine chemical industry, medicine chemical industry and the sustainable development of energy and environment. Different from single metal nanoscale catalysts, the bimetallic nanoparticles have different mixed structures. This thesis mainly studies the structural properties of the nanoscale bimetallic catalyst Au-Pt by the method of combining the computing simulation and experiment.Molecular dynamics (MD) simulations have been employed to investigate the configuration properties of Au-Pt nanoparticles with different sizes、structures、concentrations and temperatures. The icosahedral core-shell and mixed type structures with atomic number923and2057were taken as the initial configurations in this simulation. To compare with icosahedral clusters, the face-centered cubic (FCC) structure with the same number of atoms was also studied. The results demonstrate that the melting points rise as the concentration of Pt increases. A detailed analysis of structural properties by atomic pair distribution functions (PDFs) was used. The results of modeling calculation were consistent with resonant high-energy X-ray diffraction experiments.In addition, the high-energy synchrotron radiation small angle X-ray scattering (SAXS) and extended x-ray absorption fine structure (EXAFS) experiments were used for the measurement of bimetallic nanoparticles Au-Pt sample and combined with the molecular simulation method. By the data analysis, the much more accurate size analysis diagrams were obtained. It is meaningful that the application of the high-energy SAXS technology in the research of metal catalysts.