Steric Hindrance of NH₃ Diffusion on Pt(111) by Co-Adsorbed O-Atoms.

ABSTRACT: A detailed velocity-resolved kinetics study of NH₃ thermal desorption rates from p(2 × 2) O/Pt(111) is presented. We find a large reduction in the NH₃ desorption rate due to adsorption of O-atoms on Pt(111). A physical model describing the interactions between adsorbed NH₃ and O-atoms explains these observations. By fitting the model to the derived desorption rate constants, we find an NH₃ stabilization on p(2 × 2) O/Pt(111) of 0.147_-0.014^+0.023 eV compared to Pt(111) and a rotational barrier of 0.084_-0.022^+0.049 eV, which is not present on Pt(111). The model also quantitatively predicts the steric hindrance of NH₃ diffusion on Pt(111) due to co-adsorbed O-atoms. The derived dif

SUBMITTER: Borodin D 

PROVIDER: S-EPMC9716551 | biostudies-literature | 2022 Nov

REPOSITORIES: biostudies-literature