Atoms And Small Molecules In Transition Metal Adsorption, Diffusion Research

The dynamics of the interaction between the gaseous atom , molecules and solid surfaces has been paid more and more attention during the past decades with the rapid development of the chemical industry. And the surface adsorption as the key of the catalysis between different phases has taken on the more and more expansive prospect. The main contents of this work are as follows:1st chapter: this work synopsizes the significance, status in quo, methods , the existing problems of the interaction between gas and solid surface and the theoretical method in this work.2nd chapter: The interactions between atoms and metal surfaces have been solved by 5-MP. The work makes an assumption called "surface frozen approximation", takes account of the orientation affect of d electrons of transition metals, and constructs the theoretical model-5-MP. This work puts forward the concepts of vibration fingerprint of atomic adsorption state, the transmission and variance of the critical characteristics.3rd chapter: The interactions between atonu diatomic molecules and metal surfaces are studied by 5-MP and the extended LEPS potential. This work puts forward the concept of molecular vibration fingerprint.The main contribution of this work is as following:1. The adsorption and diffusion of 0-Rh systems are investigated with 5-MP in detail. The obtained data reproduce the experimental and theoretical results. This work puts forward the concept of vibration transmit property for atomic adsorption state, by analyzing the transmission and variance, the 45(47)meV, 63(65)meV from experiment are attributed to the perpendicular vibration for long-bridge site and pseudo-3-fold site respectively; for Rh(711) stepped surface, the 3-fold site on step is accustomed to be regarded as the active site, nevertheless, the conclusion that O atom resided in the 4-fold site on the (100) terrace in experiment makes one not know how to conjecture. Although the step site is the active site for the dissociation of 62 molecule, O atoms occupy 4-fold states finally at low coverage for H3 site adjacent to the step is the metastable state and its life time is short in the extreme, which is induced by the variance of critical characteristics. All make people become to oppugn the idea that the step is the active site and mistake that the property of the system deviates from the research ago. The result of this work indicates: the step is still the active site but not the most steady adsorption state, [this work has contributed to 2. O-Ru systems are investigated with 5-MP in detail. The obtained data agree with the experimental and theoretical results. This work predicts the adsorption of O atom on Ru(ll-21) by the the transmission and variance of vibration fingerprint and draws the conclusion that O atom tends to absorb on the 3-fold site. It's well known that HCP crystal lattice is hexangular compact cubic crystal so that the study about it is very difficult. Until today, there are few experimental reports and even the theoretical study doesn't appear. Therefore, this work can be called the explorer for whether experiment or theory [ this work has contributed to ≤Chem. J. Chin. Univ.≥ .3. H-Ru(ll-21) system is investigated with 5-MP. And at the same time, 2H-Ru(11-21) system is studied by 5-MP and extend LEPS potential. The work putsforward the concept of inner adsorption state and exterior adsorption state. In TDS experiment, the a state is the strong repulsive exterior adsorption state with the strong repulsive interaction with the inner adsorption state; p state is the weak repulsive exterior adsorption state; 7 state is the exterior adsorption state without interaction with the inner adsorption state. This work doesn't support the speculation that a. state is 4-fold adsorption state from experiment. Of course, there are only the laboratory in Germany and this work which are studying the system, thereby, the result of this work still needs the further demonstration [this work has been published on ({Chem. J. Chin. Univ.)} 2004, April] .4. C...