Nanoceria-energetics of surfaces, interfaces and water adsorption

The surface and interface enthalpies of CeO₂ were studied by high temperature oxide melt solution calorimetry combined with water adsorption calorimetry. The surface enthalpies of the hydrated and anhydrous surfaces are 0.86 ± 0.02 and 1.16 ± 0.02 J/m², respectively. The water adsorption enthalpies are similar for nano and bulk ceria; for the nano ceria the integral adsorption enthalpy for chemisorbed water relative to water vapor is-59.82 ± 0.74 kJ/mol with coverage of 8.79 ± 0.39 H ₂O/nm² and for the bulk it is-61.69 ± 1.26 kJ/mol with coverage of 8.15 ± 0.66 H₂O/nm². The interfacial enthalpy is 0.81 ± 0.14 J/m². The obtained energies are in good agreement with reported data from atomistic simulations and less direct experimental determinations.