Theoretical Study Of Adsorption And Dissociation On Gas - Solid Surface

In recent years, with the rapid development of chemical industry, the interactionof gaseous molecules and metal solid surface are paid much attention to by the people .In these interactions, the adsorption and dissociation are the most basic interactions.The experimental method is complex and time consuming, therefore, it is verynecessary to use the theory method to research. In this paper, some typical metalatoms and gas atoms and dual atom gas molecules are researched through 5-Morsepotential method and improved extended LEPS potential method. The researchcontent of this paper are described briefly as follows:In this paper, we choose atoms, molecules, and face-centered cubic lattice metalsurfaces as the research object, by constructing reasonable surface adsorptiondynamics model, and then the essence of the interaction is discussed in this paper.The idea of this study is to study the simple gas atoms on the metal surface atthe begining, and this as the basis for the diatomic gas molecules on the metalsurface . The long-term research objectives of our laboratory is to apply theory to thegaseous four-atom molecules on metal surface, and then extended to athe polyatomicmolecular system on the metal surface.Our laboratory have researched the Gas - solid surface interaction more than tenyears, and achieved good results,it is the mature research system.. We put forward the5-Morse potential method，it is used in N, O, C, H atoms on Pd, Ni, Ru metal surfaceand stepped surface ,and they have the good theoretical results.The improvedextended LEPS potential method is used gaseous diatomic molecules on the metalsurface,and they obtain the detailed critical characteristics.In this paper, we research H, S, O gas atoms on Al、Rh、Cu,with the5-Mpmethod.In chapter 1,it describes the meaning of study, the experimental and theoreticalmethods . 5-Morse potential method and improved extended LEPS potential method were introduced in detail.In chapter 2,the H-Al, S-Cu and S-Rh systems entirely investigated by5-Morsepotential method .In chapter 3,the O-Ag(211)(410)（997）and the O2-Ag systems are studied.The main research fruit in this work as follows:1.H-Al (100) (110) (111) system:On (100) surface adsorption, there are threetype adsorption sites, respectively is top adsorption state, bridge site and four-foldhollow site . On (110) surface adsorption, Top and short bridge sitesare adsorptionsites, triple-hole site is the diffusion transitional state. This paper has deduced that thehydrogen atoms adsorpt the top tite prioritily, and then as the increase of the coverage,occupying the short bridge site. On (111) surface adsorption, there are four typeadsorption sites, respectively is top adsorption state, bridge site and three-fold hcp siteand hcp site .2. S-Cu(100)(110)(111): The theoretical results show that S atom can onlyadsorption at the four-fold site on Cu (100): This work predicts that the four-foldhollow site is stable adsorption site on Cu (110) surface for the S atom, the three-foldsite is the most stable adsorption sites on Cu (111)surfacefor the S atom.The results ofthis work are approved by the experimental results.3. S-Rh(100)(110)(111): On (100) surface adsorption, there are three typeadsorption sites, respectively is top adsorption state, bridge site and four-fold hollowsite . On (110) surface, there are three type adsorption sites, respectively is topadsorption state,long bridge site ,short bridge site and four-fold hollow site. On (111)surface adsorption, there are four type adsorption sites, respectively is top adsorptionstate, bridge site and three-fold hcp site and hcp site .4. O-Ag(410)(211)(997): By studying the (211), (997) stepped surface , we think:in the Ag (111) flat surface, the low-frequency vibration 27.3mev, 30meV measuredby experiments,may be caused by the step . Through to (410) Stepped Surfaceresearch, we speculate that there are three types of atomic ststes ,and the most stableadsorption site is the four-fold hollow site LB which is at the bottom of the step.5. O2-Ag(100)(110)(111): On (100) surface adsorption, there are two type adsorption sites, respectively is bridge site and hollow site . On (110) surfaceadsorption, there are three type adsorption sites, respectively is bridge site along theX direct and four-fold hollow site along the x and y direct .