A molecular dynamics simulation of hydrogen atoms collisions on an H-preadsorbed silica surface

Abstract

The interaction of hydrogen atoms and molecules with a silica surface is relevant for many research and technological areas. Here, the dynamics of hydrogen atoms colliding with an H-preadsorbed -cristobalite (001) surface has been studied using a semiclassical collisional method in conjunction with a recently developed analytical potential energy surface based on Density Functional Theory (DFT) calculations. The atomic recombination probability via an Eley-Rideal (E-R) mechanism as well as the probabilities for other competitive molecular surface processes have been determined in a broad range of collision energies (0.04-3.0) eV eV) for off-normal (v=45°) and normal (v=0°) incidence and for two different surface temperatures (TS = 300 and 1000 K). H2,gas molecules form in roto-vibrational excited levels while the energy transferred to the solid surface is below of 10% for all simulated conditions. Finally, the global atomic recombination coefficient (E-R) and vibrational state resolved recombination coefficients (v) were calculated and compared with the available experimental values. The calculated collisional data are of interest in chemical kinetics studies and fluid dynamics simulations of silica surface processes in H-based low-temperature, low-pressure plasmas.