H2O decomposition on Ir (111) surface with high-reactivity at room temperature: A first-principles study

[Display omitted] •The first time Ir has been proposed for H2O decomposition.•Employed first-principles calculations to simulation the full process.•Ir (111) has comparable and even better performance compared with other metals. H2O decomposition by chemical catalyst with low energy-cost is accepted as a promising method to produce hydrogen with high-purity and no carbon monoxide. In this paper, we studied the decomposing behavior of H2O molecule on the clean and O-covered Ir (111) surface in order to explore its potential as a novel chemical catalyst for this purpose. Results indicated that the pre-adsorbed O atom can exert a prominent promotion impact for Ir (111) surface upon H2O and OH dehydrogenations, boosting their Ead and lowering the Ebar simultaneously. Given the small Ebar of 0.40 eV for H2O dehydrogenation and of 0.76 eV for OH dehydrogenation on the O-covered Ir (111) surface, we are hopeful that the H2O decomposition into separate atoms could be realized on such surface at room temperature.