Chemical compatibility of solid oxide fuel cell air electrode Pr₄Ni₃O10±δ with commercial electrolytes

The chemical reactivity between Pr 4 Ni 3 O 10±δ (3‐PNO) electrodes and Y 0.08 Zr 0.92 O 1.96 (YSZ), Ce 0.9 Gd 0.1 O 1.95 (GDC), and La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 2.85 (LSGM) electrolytes was analyzed by electrochemical impedance spectroscopy and X‐ray diffraction. 3‐PNO powders were synthesized by two different chemical routes, one of them uses hexamethylenetetramine (HMTA) as a complexing agent (route A) while the other citrates (route B). The samples observed by scanning electron microscopy presented different microstructures; route A powders present small submicronic grains with an open microstructure while route B powders are formed by larger well‐connected grains. The polarization resistance ( R P ) values for 3‐PNO/YSZ cells are one order of magnitude higher than those of 3‐PNO/GDC and 3‐PNO/LSGM cells. The R P for both cells 3‐PNO/GDC and 3‐PNO/LSGM and its evolution in time suggest that chemical reactivity takes place during the adhesion treatment and electrochemical measurements. The microstructure plays a crucial role in R P and the degradation rate; 3‐PNO obtained by route A (3‐PNO‐HMTA) exhibits the best electrochemical performance since these powders present a well‐loose morphology and a large exposed area. However, this fact makes them active chemically, so the increase of R P with time is slower for 3‐PNO electrodes prepared by route B (3‐PNO‐Cit), since the rate of chemical reactivity with the electrolyte is slower.