Thermochemistry of the reaction between SrCO₃ and CeO₂ as

SrCO₃(s) + CeO₂(s) = SrCeO₃(s) + CO₂ (g)

was studied over the temperature range 1113–1184K. The equilibrium pressure of CO2(g) over the ternary phase mixture of SrCO₃(s), CeO₂(s) and SrCeO₃ (s) was measured at various temperatures using a tensimetric apparatus. The temperature dependence of the measured CO₂ (g) pressure could be represented as

Log (рCO₂ (Pa)) (± 0.04) = – 11534(±750)/T+13.1(±0.7), (1113≤T (K) ≤1184).

Tensimetric measurements were also carried out for the decomposition of SrCO₃(s).The equilibrium vapor pressures of CO₂ (g) over the biphasic mixture of SrCO₃(s) and SrO(s) could be represented as

Log pCO₂ (Pa) (±0.01) = –11139(±263)/ T+12.72(±0.2), 1045≤T (K) ≤1123).

The observed CO₂ pressures were compared with those obtained for reaction (1). Simultaneous thermogravimetric/differential thermal analysis experiments were carried out for reaction (1) and for the decomposition of SrCO₃ in CO₂ atmospheres. All these results were used to derive the thermodynamic properties of SrCO₃(s) and SrCeO₃(s).