Abstract:
Adsorption behaviors of four typical noble metals (Au, Pd, Pt, and Rh) on the CeO
2(111) surface were systematically investigated by using density functional theory method. The results indicated that Au prefers to be adsorbed on the atop site, while Pd and Pt on the O-bridge site. Rh adsorbed on the 3-fold hollow site is the most stable configurations. When the noble metals are adsorbed on the atop site, the adsorption strength is in the order of Pt > Rh > Pd > Au. New electronic peaks are present between the Ce 4
f and O 2
p peaks when Pd, Pt, and Rh atoms are adsorbed on the CeO
2(111) surface, while no peak is found for the adsorption of Au; the
d electronic peak of Au overlaps with the O 2
p peaks at-4 to-1 eV. According to the density of states (DOS) analysis, when Au is adsorbed on the atop site, Pd and Pt on the bridge site, and Rh on the 3-fold hollow site, their interactions with surface oxygen atoms on the CeO
2(111) surface are stronger than other configurations, which is in good agreement with the results of Bader charge population.