Abstract
We report the effect of PrOx addition on the oxygen reduction reaction (ORR) mechanism of a [Ca2CoO3-δ]q[CoO2] SOFC cathode (also known as Ca3Co4O9-δ, C349) obtained by solid-state synthesis of a stoichiometric mixture of mollusk shell powder (a natural source of calcium carbonate) and cobalt oxide. Symmetrical cells of screen-printed pristine C349 and PrOx-infiltrated C349 compositions are analyzed by electrochemical impedance spectroscopy (EIS) as a function of oxygen partial pressure (pO2 = 1-10−2 atm) in the temperature range 600–800 °C. The results show a decrease in total polarization resistance (Rp) of ∼8 times by the addition of PrOx to the C349 phase in pure oxygen at 700 °C. This improvement is shown to be mainly due to a large decrease (∼13 times) in the charge-transfer processes occurring at the surface of electrode, which dominate the total polarization resistance. The polarization resistance of the PrOx-impregnated C349 cathode is also demonstrated to be very competitive in comparison to typical Ca-cobaltite-based cathodes.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
