Nouvelle publication

An efficient hierarchical nanostructured Pr6O11 electrode for solid oxide fuel cells
R. K. Sharma, E. Djurado
J. Mater. Chem. A 2018, 6, 10787
A hierarchical nanostructured Pr6O11 phase, a potential electrocatalyst for the oxygen reduction reaction, is
prepared for the first time by electrostatic spray deposition (ESD) on a GDC (Ce0.9Gd0.1O2
d) electrolyte
and evaluated as an Intermediate Temperature Solid Oxide Fuel Cell cathode. Different and innovative
microstructures are found to be related to the solvent composition, deposition time, nozzle to substrate
distance, substrate temperature and solution flow rate. Single phase Pr6O11 films crystallize in a Fm
-3m
fluorite cubic structure after calcination at 700 °C for 2 h in air. The electrochemical properties are
found to be strongly dependent on the microstructure of the cathode films. A symmetrical cell based on
the double layer architecture (a columnar-type active layer by ESD topped by a screen-printed current
collector) cathode presents a low polarization resistance value of 0.02 Ω cm2 at 600 C. To the best of
our knowledge, this Pr6O11 cathode shows the best performance reported to date for all SOFC cathode
materials. A single cell made of a commercial (Ni-3YSZ/Ni-8YSZ/8YSZ/GDC) half cell and this double
layer cathode delivers a maximum power density of 500 mW cm
-2 at 700 °C. Moreover, Pr6O11 does not
show any reactivity with GDC over 10 days in air at 800 °C.