K 2 CO 3 Solid Electrolyte as a CO 2 Probe: Decomposition Measurements of CaCO3

Abstract

An electrochemical cell using a solid electrolyte has been employed as a gas probe to measure the equilibrium partial pressure of carbon dioxide in air mixtures at 1 atm total pressure in the temperature range of 575–1025 K. Stable reversible emf's have been obtained in gas mixtures containing as little as 9 ppm in air. The carbonate cell has also been used to measure the standard Gibbs energy change associated with the dissociation of calcium carbonate into calcium oxide and carbon dioxide in the temperature range of 725–975 K. The thermodynamic results are in good agreement with the published data from the literature, thus validating the use of as a probe.