Temperature programmed oxygen desorption and sorption processes on Pr2-xLaxNiO4+δ nickelates

Abstract

The present work is devoted to the investigation of temperature programmed oxygen desorption - sorption (TPD) processes performed on SOFC innovative cathode materials with Pr2-xLaxNiO composition. The experiments were performed using the coulometric titration technique involving an, over the temperature cycle 20 900 20 parameters were the time and temperature dependences of both the titration current and the oxygen over-stoichiometry. TPD spectra of Pr2-xLaxNiO (x 0) exhibited two sharp peaks (maxima) of titration current with excellent resolution at p(O2) = 50 Pa, induced by removal of oxygen from different sites of the crystal lattice. TPD spectrum of Pr2NiO recorded under the same conditions drastically differs from the spectra of Pr2-xLaxNiO as four sharp maxima of titration current are detected. The TPD spectra of Pr2-xLaxNiO then strongly depend on the nature of the rare-earth (La or Pr) in link with the oxygen over-stoichiometry amount.