Water formation reaction on Pt(111): Role of the proton transfer

The catalytic water formation reaction on Pt(111) was investigated by kinetic Monte Carlo simulations, where the interaction energy between reaction species and the high mobility of H2 O molecule was considered. Results obtained clearly reproduce the scanning tunneling microscopy images which show that the reaction proceeds via traveling the reaction fronts on the O-covered Pt(111) surface by creating H2 O islands backwards. The reaction front is a mixed layer of OH and H2 O with a (3×3) R30° structure. Coverage change during the reaction is also reproduced in which the reaction consists of three characteristic processes, as observed by the previous experiments. The simulation also revealed that the proton transfer from H2 O to OH plays an important role to propagate the water formation.