The standard Gibbs free energies of the following reactions: Co + 1 2 O2 ⇄ CoO (1) and 3CoO + 1 2 O2 ⇆ Co3O4 (2) have been calculated from the e.m.f. measurements carried out using a simple compartment solid state galvanic cell, as well for the reaction: 3Co + 202 ⇆ Co3O4 (3) The temperature-equilibrium oxygen partial pressure relationship has been evaluated. A phase diagram for Co, CoO and Co3O4 is proposed in the temperature range 600-900 °C. A statistical analysis on reported ΔGf0 values at 1100 K for reaction (1) has been performed and the results are discussed.
Narducci, D., Negroni, F., Mari, C. (1985). High temperature standard Gibbs free energy determination for Co-O systems by e.m.f. measurements. A statistical approach to evaluate reliability of the current method. MATERIALS CHEMISTRY AND PHYSICS, 12(4), 377-388 [10.1016/0254-0584(85)90107-5].
High temperature standard Gibbs free energy determination for Co-O systems by e.m.f. measurements. A statistical approach to evaluate reliability of the current method
NARDUCCI, DARIO;MARI, CLAUDIO MARIA
1985
Abstract
The standard Gibbs free energies of the following reactions: Co + 1 2 O2 ⇄ CoO (1) and 3CoO + 1 2 O2 ⇆ Co3O4 (2) have been calculated from the e.m.f. measurements carried out using a simple compartment solid state galvanic cell, as well for the reaction: 3Co + 202 ⇆ Co3O4 (3) The temperature-equilibrium oxygen partial pressure relationship has been evaluated. A phase diagram for Co, CoO and Co3O4 is proposed in the temperature range 600-900 °C. A statistical analysis on reported ΔGf0 values at 1100 K for reaction (1) has been performed and the results are discussed.
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
