Atomic and molecular adsorption on Pd(111)

The adsorption properties of a variety of atomic species (H, O, N, S, and C), molecular species (N-2, HCN, CO, NO, and NH3) and molecular fragments (CN, NH2, NH, CH3, CH2, CH, HNO, NOH, and OH) are calculated on the (111) facet of palladium using periodic self-consistent density functional theory (DFT-GGA) calculations at 1/4 ML coverage. For each species, we determine the optimal binding geometry and corresponding binding energy. The vibrational frequencies of these adsorbed species are calculated and are found to be in good agreement with experimental values that have been reported in literature. From the binding energies, we calculate potential energy surfaces for the decomposition of NO, CO, N-2, NH3, and CH4 on Pd(111), showing that only the decomposition of NO is thermochemically preferred to its molecular desorption. (c) 2012 Elsevier B.V. All rights reserved.