Misfit-type Ca₃₋<i>_x</i>La<i>_x</i>Co₄O₉₊<i>_δ</i> (<i>x</i>=0, 0.3) oxides were synthesised to be evaluated as possible cathode materials for proton conducting fuel cells (PCFCs) based on BaCe_0.9Y_0.1O₃₋<i>_δ</i> (BCY10) dense ceramic electrolyte. The electrical conductivity value of Ca_2.7La_0.3Co₄O₉₊<i>_δ</i> (<i>σ</i>≈53 S cm^–1 at 600 °C) is in the range of usually required value for a cathode application (about 50–100 S cm^–1). In order to test the performance of each compound as cathode material, impedance measurements were carried out on Ca₃₋<i>_x</i>La<i>_x</i>Co₄O₉₊<i>_δ</i>/BaCe_0.9Y_0.1O₃₋<i>_δ</i>/Ca₃₋<i>_x</i>La<i>_x</i>Co₄O₉₊<i>_δ</i> symmetrical half cells over the temperature range 400–800 °C under wet air. A promising electrocatalytic activity has been observed with both compounds Ca₃Co₄O₉₊<i>_δ</i> and Ca_2.7La_0.3Co₄O₉₊<i>_δ</i>. Factually, the area specific resistance obtained was about 2.2 Ω cm² at 600 °C.Read less <