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 H2O/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.