Table 5. Adsorption Energy of H₂O on Lattice Defects and Defect Clusters^a.

lattice defect and cluster	n(Pt2+)/n(Ce3+)	Ef (eV)
PtCe″-VO·· + H2O	∞	1.59
2CeCe′-VO·· + 2H2O	0.0	0.49
2CeCe′-PtCe″-2VO·· + 3H2O	0.5	0.48

^an(Pt²⁺) and n(Ce³⁺) are the number of lattice defects of Pt²⁺ and Ce³⁺.