Effects of Fe doping on oxygen vacancy formation and CO adsorption and oxidation at the ceria(111) surface

• After Fe doping, the oxygen vacancy formation energy of the doped ceria(111) is reduced.
• The Fe dopant induces large perturbation on the geometric and electronic structure of Ce0.92 Fe0.08O2 (111) surface.
• The Fe dopant facilitates the formation of surface oxygen vacancies and enhances the reaction of CO on the surface.
• On the Fe doped ceria(111) surface two types of adsorption of CO molecule are found: physisorbed CO and formed CO2.

To get insight into the catalysis effect of Fe doping in the CeO2, the structures and electronic properties of Fe-doped CeO2(111), and CO adsorption on the Ce0.92 Fe0.08O2(111) surface are investigated by using the DFT + U method. The oxygen vacancy formation energy of the Fe-doped ceria(111) is reduced and the Fe dopant tends to be the center of oxygen vacancy clusters. On the Ce0.92 Fe0.08O2(111) surface two types of adsorption of CO are found: physisorbed CO and formed CO2. For the former, the molecule remains intact and for the latter, a CO2 molecule releases and an oxygen vacancy forms on the surface.

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