Thermodynamic stability and hydration enthalpy of strontium cerate doped with yttrium

The standard molar enthalpy of formation of SrY0.05Ce0.95O2.975 has been derived by combining the enthalpy of solution in 1 M HCl + 0.1 KI with auxiliary literature data, ΔfH° (SrY0.05Ce0.95O2.975, s, 298.15 K) = −1720.4 ± 3.4 kJ/mol. The formation enthalpy of SrY0.05Ce0.95O2.975 from the mixture of binary oxides is ΔoxH° (298.15 K) = −45.9 ± 3.4 kJ/mol and the enthalpy of reaction of SrY0.05Ce0.95O2.975 with water forming Sr(OH)2, CeO2, and Y2O3 is ΔrH° (298.15 K) = −85.5 ± 3.4 kJ/mol. Our data and the entropies of different substances show that SrY0.05Ce0.95O2.975 is thermodynamically stable with respect to a mixture of SrO, Y2O3, CeO2 and that the reaction of SrY0.05Ce0.95O2.975 with water is thermodynamically favourable.