Atoms And Molecules In Ru, Ni And Ta Metal Surface Adsorption Behavior Of Periodic Density Functional Theory Study

The interaction of hydrogen with transition-metal surfaces is of considerable interest not only because of its practical importance for electrochemistry and catalysis, but in view of comparison with experimental and theoretical results. Ruthenium is one of the most important catalysts in the synthesis of hydrocarbons with H and CO2. Nickel had been used as catalysts with particularity that it produces methane with an almost total absence of heavier hydrocarbons. Detailed knowledge of the chemisorption of atoms and molecules on the surfaces would be very useful to gain some insight into the nature of the interaction between adsorbates and substrates and to understand the corresponding catalytic processes. Within decade years ascribe to the increasing of computation level and method, the Density Functional Theory(DFT) has gone through a rapid development, and has been used to investigate the transition metal system. In this paper, a systematic investigation of hydrogen or carbon monoxide on Ru(001), Ni(111) and Ta(001) surface has been carried out by means of periodic DFT calculations.1. For hydrogen on Ru(001) surface, under different hydrogen atom monolayer, we calculated the structure, energy, vibrational frequency and work function change and confirmed the favorite adsorption site is fcc site. At 0.5MlL, three peaks were found. Our data reappearanced the current of work function change.2. For hydrogen and carbon monoxide on Ni(111) surface, considering of the different monolayer and adsorbate structures, we calculated the structure, energy, vibrational frequency and density of states. Our data showed the favorite adsorption site is H at fcc and CO at hcp. The Density of State(DOS) analysis has shown that there is charge redistribution in coadsorption system.3. For hydrogen on Ta(001) surface, the calculated result does not support a recent LEED and HREELS observation. Our results showed that the most favorite adsorption site is bridge site. The structure, energy, vibrational frequency and work function change were compared with those on W(001) surfaces.