DFT determination of ammonia adsorption configurations on the Pt{1 0 0}–(1 × 1) surface at low coverage

DFT is used to determine the ammonia adsorption configurations at low coverage on the Pt{1 0 0}–(1 × 1) surface. At 0.11 and 0.22 ML ammonia molecules adsorb in the on-top configuration with the N-atom binding to a surface Pt atom (α-NH3). We report an ammonia dimer stable at 0.22 and 0.33 ML with one molecule adsorbed in the α-state and a second one bonded via H-bond to the first molecule (β-state). At 0.33 ML the monomer and dimer coadsorption is the preferred configuration. The estimated saturation coverage for the α-state is 0.29 ML.