Monte-Carlo simulation of kinetics of H2 molecular adsorption

Effects of accommodation, desorption activation energy and lateral interaction in the kinetics of low-temperature molecular hydrogen and deuterium adsorption on W(1 1 0) and Mo(1 1 0) surfaces have been studied by the Monte-Carlo simulations. Recently reported significant dependence of the adsorption characteristics on variation of the H2 flux is explained in terms of changing proportion between incident and desorption fluxes and improved accommodation for the hydrogen molecules at high incident fluxes. Derived from the best fit to experimental plots, the activation energies for molecular hydrogen desorption are found to be of 14.6 and 14.4 meV for W(1 1 0) and Mo(1 1 0) surfaces, respectively, while the lateral interaction can be attributed to a dipole–dipole repulsion between adsorbed H2 molecules.