CHROMIUM VAPOR SPECIES OVER SOLID OXIDE FUEL-CELL INTERCONNECT MATERIALS AND THEIR POTENTIAL FOR DEGRADATION PROCESSES

Alloys protected from corrosion by a chromia scale and LaCrO3-based pe rovskites are used as materials for the interconnect of solid oxide fu el cells (SOFCs). The chromium vaporization of these materials was stu died by thermochemical modeling. Partial pressures of the vaporizing s pecies were determined for different O-2 and H2O concentrations in the oxidizing gas. CrO2(OH)(2)(g) and CrO3(g) are the most abundant speci es in air with and without humidity, respectively. The potential of th e Cr-containing vapor species for the degradation of the electrical pr operties of an SOFC was analyzed by thermodynamic computations. The el ectrochemical reduction of the Cr-containing vapor species at the cath ode/electrolyte/gas phase boundary can lead to polarization losses.