Theoretical Study Of Adsorption Dynamical Behaviour And Adsorption Dynamical Model On Surfaces

The dynamics of gas-surface interaction is awaking more and more interest in the community of physicists and chemists. The adsorption of oxygen on Ag in particular has been intensively studied hi the past because of the importance of Ag as a catalyst in ethylene epoxidation. For a time, oxygen chemisorption structures on Cu surfaces belong to the most studied of all adsorption phases. In this paper, we investigated the O-Ag, O-Cu interaction systems entirely by constructing atom-surface interaction potential, named five parameters Morse potential (5-MP for short). This will made a way to the study of gaseous two-atom molecule-surface interaction. Moreover, the analytical potential of gaseous three-atom molecule HjO interaction system has been constructed. On the basis, we have gained the equilibrium characteristics of the ground state of gaseous H2O and got insight into the channel reaction. All this will be helpful to the further study to the interaction system of gaseous three-atom molecule-surface and enhance confidence to the solution of multi-atom molecule-surface interaction problem.In Chapter 1, the elementary theory for calculation in this paper and the surface cluster model are given. In Chapter 2, we dealt with the O-Ag(100), (110), (111) plane surface system comprehensively, using the 5-MP method, which make it possible for people to understand this key system detailedly and completely. With regard to the adsorption of 0 atom on the Ag (111) surface, our calculation results suggest that the abnormally low vibration of 27.3, 30meV of EELS experimental results should be resulted by the effect of the sparse steps to the nearest neighbouring hollow site on the Ag (111) terrace. The investigation to 0 atom adsorbed on the Ag (211), (997), (410) step surfaces also gained better calculation results. Calculation results for O-Cu interaction systems are collected in Chapter 3. Both the three low index Cu(100), (110), (111 )and step defective surfaces Cu (211), (410), (311) are calculated.Because there is no sound analytical potential of gaseous three-atom molecule interaction available, we have proposed a concept of two-body perturbation potential. This is thepreliminary and indispensable step to the investigatin to the interaction of gaseous three-atom molecule-surface system. The main thought of our potential is to divide the multi-body interaction into the sum of several two-body interactions. And the atoms out of the two of the pair of the two-body interaction are all regarded as perturbation atoms to the pair, and express the two-body interaction with Morse potential or other pair-potential. By adding perturbation item into the two-body potential expression, the interaction between a perturbation atom and a pair can be embodied. Herein, we can get the two-body perturbation potential. And, accordingly, multi-body potential can obtained by adding. In Chapter 4, we have succeeded constructing an analytical potential for gaseous H2O, and simulated the channel reaction of H2O. The results are enjoying good agreement with experimental data and better than the results of other theory and the former calculation of our own. In the previous study to gaseous CO2, our disposal using the two-body potential is also famous.