Effects of oxygen vacancy and Pt doping on the catalytic performance of CeO₂ in propane dehydrogenation : A first-principles study

The catalytic properties of the CeO₂ catalyst for propane dehydrogenation (PDH) are examined by employing the density functional theory calculations. Surface modifications and their effects on the surface reactivity are explored by creating the oxygen vacancy and single Pt atom doping. A comparative study between the binding energies of the different PDH reaction species reveals a considerable Lewis acid-base interaction over the pristine and defective surfaces, which dominantly strengthens the bond formation between the adsorbates and the catalyst surface, resulting in the enhancement of surface reactivity. The creation of oxygen vacancy and doping the CeO₂(111) surface with single Pt atoms changes the charge distribution over the surface on account of excess 4f electrons. This electronic change increases the bond formation abilities of the inactive Ce atom and hence increases the adsorption strength. Oxygen vacancy in the defective CeO₂(111) surface migrates over the surface with the addition of an appropriate adsorbate. Moreover, it is revealed that the propylene is more strongly adsorbed on the single-Pt-atom-doped CeO₂(111) surface than the pristine and defective surfaces, which decreases the deep dehydrogenation energy barrier and ultimately results in the lowering of the selectivity.