Hydrogen Adsorption on PdGa(110): A DFT Study

P. BECHTHOLD; P. JASEN; E. GONZÁLEZ; A. JUAN

JOURNAL OF PHYSICAL CHEMISTRY C

AMER CHEMICAL SOC

Lugar: Washington; Año: 2012 vol. 116 p. 17518 - 17524

1932-7447

CO adsorption is analyzed using density functional theory (DFT) calculations. Changes in the electronic structure of PdGa(110) surface and CO bond after adsorption are addressed. CO is located only on Pd atop geometry with a tilted configuration (9.13° from the perpendicular) and no interaction with Ga is detected. The Pd-Pd bond strength decreases 54.2 % as the new Pd-CO bond is formed. The C-O bond length change less than 1% compared to the vacuum but its strength decrease 46.2% as determined by the changes in the overlap population. The effect of CO is limited to its first Pd neighbor. Analysis of orbital interaction reveals the Pd-CO bond mainly involves s-s and s-p orbitals with less participation of Pd 4d orbitals. The computed CO vibration frequencies after adsorption shows a red shift from vacuum to ward 2013.85 cm-1, which agrees with previous experimental data on PdGa intermetallic.