Modeling of phase transitions and reaction between coadsorbed oxygen and hydrogen on Pd(111)

We propose kinetic Monte Carlo simulation of O and H co-adsorption experiment on Pd(111). At 200 K we obtain structural phase transition (2 x 2)o → (√3x√3)o with increase of H-coverage by considering O-O, H-H and O-H interactions and several kinetical processes. We also demonstrate how reverse phase transition (√3x√3)o → (2 x 2)o occurs at T = 205 K due to hydrogen dissolution into the bulk when hydrogen income is terminated. At higher temperature we observe the vanishing of (2 x 2)o oxygen islands due to water-formation reaction for different reaction rates and paths