Abstract: PrNi1-xCoxO3-δ – Ce0.9Y0.1O2-δ composites are promising as IT SOFC cathodes provided their sintering conditions are optimized [1]. In this work effect of microwave sintering (MS) on properties of such materials is studied. Perovskite (P) PrNi0.5Co0.5O3-δ (PNC) and fluorite (F) Ce0.9Y0.1O2 (YDC) oxides were synthesized by Pechini route. PNC‒YDC composites were prepared by ultrasonic dis-persion. Pellets were sintered at 870 – 1100 °C using specially designed microwave set-up. Samples were characterized by XRD and TEM with EDX. Oxygen mobility was estimated by O2 TPD and oxygen isotope heteroexchange with 18O2 and C18O2. MS provides dense materials (porosity < 10 %) even at the lowest temperatures. PNC is single-phase P. Composites are comprised of P+F phases with Pr6O11 admixture, strong elements redistribution between P and F domains occurs. The total amount of oxygen desorbed is up to 20 monolayers for PNC and 70 monolayers for PNC–YDC, being ~ 1.5 times higher as compared to conventionally sintered (CS) samples. This is due to a higher disordering of P and F domains as well as their boundaries. The oxygen isotope exchange is characterized by R2 mechanism with the surface exchange constant ~10 6 cm/s and the oxygen tracer diffusion coefficient ~10 8 cm2/s at 700 °C (Table 1), being close to CS samples made at higher temperatures [1]. Hence, MS at lower temperatures provides even better functional characteristics of PNC‒YDC nanocomposite cathodes.

Cite: Sadykov V.A. , Eremeev N.F. , Bolotov V.A. , Tanashev Y.Y. , Fedorova Y.E. , Amanbaeva D.G. , Bobin A.S. , Muzykantov V.S. , Sadovskaya E.M. , Pelipenko V.V. , Lukashevich A.I. , Krieger T.A. , Ishchenko A.V.
Microwave Sintering of IT SOFC Cathode Materials Based on Praseodymium Nickelates-Cobaltites
15th International Conference on Microwave and High Frequency Heating (AMPERE 2015) 14-17 Sep 2015