Proton conduction at the surface of Y-doped BaCeO3and its application to an air/fuel sensor

Abstract

25 mol% Y3+-doped BaCeO3 (BCY25) showed an extremely low activation energy of 0.3 eV for proton conduction at the surface. The resulting overall conductivity at the surface reached 8.24 × 10−3 S cm−1 at 400°C, which was 3, 8, and 28 times higher than those in the bulk of BCY25, 20 mol% Sm3+-doped ceria, and 8 mol% yttria-stabilized zirconia, respectively. Such fast proton conduction enabled an air/fuel (A/F ) sensor using BCY25 as the solid electrolyte to work above 150°C for H2 and above 250°C for C2H4.