Gibbs energy of formation of bismuth(III) oxide

[Display omitted] •Electrochemical measurement of standard Gibbs energy of formation of Bi2O3.•A novel closed cell design with buffer electrode to avoid electrode polarization.•The results are discussed in comparison with earlier studies.•The results are in agreement with thermal data.•A complete thermodynamic data table for Bi2O3 is presented. The standard Gibbs energy of formation of Bi2O3 has been measured using a solid-state cell incorporating yttria-stabilized zirconia as the electrolyte and pure oxygen as the reference electrode. An innovative cell design, with a buffer electrode to absorb the electrochemical flux of oxygen through the electrolyte caused by trace electron/hole conduction, was used to measure the oxygen chemical potential over phase mixture Bi+Bi2O3 in the temperature range from 800 to 1473K. A closed cell was used to avoid possible deviations from equilibrium caused by vaporization of bismuth and oxides of bismuth. The results for α-Bi2O3 in the temperature range from 800 to 1002K can be summarized by, ΔGfo(±230)/J mol−1=−584235+289.28(T/K) For δ-Bi2O3 in the temperature range from 1002 to 1078K: ΔGfo(±230)/J mol−1=−553669+258.77(T/K) The results are discussed in relation to thermodynamic information reported in the literature.