A mechanistic study of H2S adsorption and dissociation on Cu2O(1Â 1Â 1) surfaces: Thermochemistry, reaction barrier

► H2S molecularly adsorbed on perfect and sulfur-containing Cu2O(1 1 1) surfaces. ► Dissociative adsorption of H2S occurs predominantly on oxygen-vacancy surface. ► Vibrational frequencies of adsorbed species can guide experimental IR spectroscopy. ► The presence of surface S atom goes against the HS bond-breaking of H2S process.