DFT study of adsorption and diffusion of atomic hydrogen on metal surfaces

Abstract

An extensive study of adsorption and diffusion of hydrogen atoms on (100) surfaces of fcc Au, Cu, Ag and P t was performed by means of DFT calculations. Bulk properties of those metals were calculated and compared with previous results. The adsorption distances and energies of the hydrogen atom on top, hollow and bridge sites of the (100) surfaces were calculated in order to elucidate preferential adsorption sites of hydrogen on each metal. All these calculations were done in conjunction with a study of charge distribution. Finally, diffusion of the H atom from the most stable adsorption site to the nearest neighbouring site was studied in order to obtain diffusion barrier and diffusion velocity values. The highest diffusion velocity was found to be v = 6.44 × 10 11 s −1 for the case of Ag, whereas the lowest was v = 1.13 × 10 7 s −1 for Au.

Adsorption Energetics of Atoms and Diatomic Gases with Electrocatalysis Approach towards Hydrogen and Oxygen Evolution Reaction on Pt Surfaces

“…These are the key reactions for improving air quality, especially in the automotive industries, where platinum is used as the active metal in three‐way catalyst . Over the past few decades, the interaction of atoms or molecules with the platinum surfaces are intensively studied in surface science and achieved a great deal of attention both experimentally as well as computationally majorly due to its scientific and industrial importance in chemical and petroleum applications.…”

“…Furthermore, the chemisorption of atoms (H, C, N, O, and S) takes an important role in the reactions of the chemical industries mainly contained in the reactions of hydrocarbon production, ammonia synthesis, oxidation, corrosion, and petroleum re‐forming . The intrinsically fundamental interest of the interaction of atoms with metal surfaces is relevant to catalytic chemistry.…”

“…Nevertheless, platinum is one of the most expensive metal and consequently, our main interest is to modify its properties to achieve higher activity or selectivity in a catalytic reaction so that less metal would be required. In this regard, computational simulations can deliver useful and rational perspectives into chemical reactions by predicting a system's geometric and/or electronic structure at the atomic scale …”

“…Atomic and molecular interactions of hydrogen,,− and oxygen,−, are most intensively and extensively studied on platinum surfaces which play an important role in numerous processes central to clean energy sources. Simultaneously, it will provide a platform to study the hydrogen/oxygen bonding between intermediates for the many chemical reactions which are performed on the transition metal surfaces.…”

“…Simultaneously, it will provide a platform to study the hydrogen/oxygen bonding between intermediates for the many chemical reactions which are performed on the transition metal surfaces. In the past few decades, countless experimental and DFT studies have been carried out for atomic hydrogen,,− and oxygen,−, adsorption on platinum surfaces and found that the fcc hollow is the most stable adsorption site on Pt(111) surface whereas hcp and top are less stable for the adsorption of H and O. However, for the Pt(100) surface bridge site is the most promising site.…”