BaCe1 − xYxO3 − δ (BCY) and BaCe0.8 − yZryY0.2O3 − δ (BCZY) perovskite mixed metal oxides were synthesised by an aqueous sol-gel technique to be investigated for their suitability in intermediate-temperature catalytic applications such as Electrochemical Promotion of Catalysis. The hydration capacity and the stability under CO2 environments of the samples were studied using thermogravimetric analysis. Based on the evaluation of these properties, BaCe0.6Zr0.2Y0.2O3 − δ (BCZ20Y20) was selected as the membrane support for wireless Electrochemical Promotion for CO oxidation on Pt. In a dual-chamber reactor, the use of H2/H2O flow in the sweep side induced promoting species supply to the catalyst in the reaction side of the reactor. Moderate promotion of the catalytic rate up to 10% was observed for temperatures up to 650 °C, while this promotional effect was reversible and repeatable. The encouraging preliminary catalytic experiments together with the membrane’s stability under the applied conditions reinforce the candidacy of BCZY membranes for intermediate-temperature applications in catalytic membrane reactors.