Density functional theory study of p ‐chloroaniline adsorption on Pd surfaces and clusters

The adsorption mode of aromatic molecules on transition metal surfaces plays a key role in their catalytic transformation. In this study, by means of density functional theory calculations, we systematically investigate the adsorption of p ‐chloroaniline on a series of Pd surfaces, including stepped surfaces, flat surfaces, and clusters. The adsorption energies of p ‐chloroaniline on these substrates [Pd(221), Pd(211), Pd(111), Pd(100), Pd 13 ‐icosahedral, Pd 13 ‐cubo‐octahedron, Pd 55 ] are −1.90, −2.13, −1.70, −2.11, −2.53, −2.65, −2.23 eV, respectively. Benzene ring is adsorpted on catalyst rather than amine group in p ‐chloroaniline molecular. A very good linear relationship is further found between the adsorption energies of p ‐chloroaniline and the d ‐band center of both Pd surfaces and clusters. The lower of d ‐band center of Pd models, the stronger adsorption of p ‐chloroaniline on catalysts. In addition, the frontier molecular orbital and density of states analysis explain the adsorption energy sequence: cluster Pd 13  > stepped Pd(221) surface > flat Pd(111) surface. © 2014 Wiley Periodicals, Inc.