Hydroxyl desorption from platinum in the catalytic formation and decomposition of water

Abstract

The water formation and decomposition reactions on Pt and the presence of intermediate OH were investigated by simultaneously measuring the OH desorption rate (by laser-induced fluorescence) and the overall H2O formation rate at different H2/O2 and H2O/O2 mixtures. These measurements were combined with computer modeling of the reactions to yield information about the reaction kinetics, e.g., about the relative importance of two different H2O formation steps (H+OH and OH+OH, respectively) in different reaction parameter regimes. A numerical value for the OH bond strength to the Pt surface was obtained from the observed temperature dependence of the OH desorption.