First principle calculations of nitric oxide on metallic Pt (1 1 1) and Pt (1 0 0), and bimetallic Au/Pt (1 1 1) and Au/Pt (1 0 0) surfaces

Abstract

The chemisorption of NO on pure Pt (111) and Pt (100), bimetallic Au/Pt (111) and Au/Pt (100) surfaces has been investigated using the pseudo-potential plane-wave method within the generalized-gradient approximation density functional theory (GGA+DFT). The results show that different surfaces have various effects on the adsorption of NO. NO tends to be adsorbed on site coordinated with more Pt atoms, and the substitution number of the top-layer Pt by Au atoms affect the d-band center and adsorption energy. The local density of states of various surfaces are calculated. With the increasing atomic number of surface Au, the d-band center moves away from the Fermi level, and the adsorption energies decrease. The further electronic states analysis reveals that the interaction between NO and metal surfaces is mainly via the hybridization of NO 5σ/2π* orbitals and metal d-bands. And when the top-layer concentrations of Au are equal, Au/Pt (100) exhibits better catalytic toward NO adsorption than Au/Pt (111). It indicates that different compositions and facets can produce varied catalytic effects.