The adsorption of acrolein on a Pt (1 1 1): A study of chemical bonding and electronic structure

The adsorption of acrolein on a Pt (1 1 1) surface was studied using ab-initio and semiempirical calculations. Geometry optimization and densities of states (DOS) curves were carried out using the Vienna Ab-initio Simulation Package (VASP) code. We started our study with the preferential geometries corresponding to the different acrolein/Pt (1 1 1) adsorption modes previously reported. Then, we examined the evolution of the chemical bonding in these geometries, using the crystal orbital overlap population (COOP) and overlap population (OP) analysis of selected pairs of atoms. We analyzed the acrolein intramolecular bonds, Pt (1 1 1) superficial bonds and new moleculesingle bondsurface formed bonds after adsorption. We found that Ptsingle bondPt bonds interacting with the molecule and acrolein Cdouble bond; length as m-dashO and Cdouble bond; length as m-dashC bonds are weakened after adsorption; this last bond is significantly linked to the surface. The obtained Csingle bondPt and Osingle bondPt OP values suggest that the most stable adsorption modes are η3-cis and η4-trans, while the η1-trans is the less favored configuration. We also found that C pz orbital and Pt pz and image orbitals participate strongly in the adsorption process.