Characterization of the High-Temperature Properties of BaCe 0.4 Zr 0.4 Pr 0.2 O 3−δ Perovskite as a Potential Material for PC-SOFC

BASBUS, JUAN; ARCE, MAURICIO DAMIAN; TROIANI, HORACIO E; PRADO, FERNANDO; MOGNI, LILIANA V.; SERQUIS, ADRIANA

NEW JOURNAL OF CHEMISTRY

ROYAL SOC CHEMISTRY

Año: 2021

1144-0546

Compounds based on barium cerates and zirconates Ba(Ce,Zr)O3−δ are oxides able to transport protons through their crystal lattice by proton hopping between oxygen sites. This feature makes them potential candidates as electrolyte for Proton Conducting Solid Oxide Fuel Cell (PC-SOFC). Pr-doping on these family compounds decreases sintering temperature and introduces electronic conductivity. This work presents a systematic study of the high temperature properties of the BaCe0.4Zr0.4Pr0.2O3−δ (BCZP) perovskite in view of its potential application as PC-SOFC cathode. At room temperature, BCZP presents rhombohedral structure, which transforms reversibly to cubic at 550 °C in dry air. Electrical measurements under dry and wet air with water vapor (~ 2 % H2O) and heavy water vapor (~ 2 % D2O) were employed to study the conductivity over a wide temperature range. The total conductivity data exhibit behavior changes between 400 and 600 °C which could be associated to a crystal structure transition. BCZP presents low total conductivity (64 µScm-1 at 600 ºC), which limits its applications as single phase cathode material. However, the material has good thermomechanical compatibility with electrolytes (~ 11 .10-6 K-1) and high CO2 tolerance (T > 900 ºC). These properties suggest that this compound could be used as oxide support for composite or backbone for impregnated electrodes, or as buffer layer to avoid degradation mechanisms while improving the performance of another cathode material.