Boosting electrocatalytic performance of BaPrO3-δ −based cathode catalysts by Co and Ni co-doping for protonic ceramic fuel cells

Achieving both high catalytic performance and low thermal expansion coefficient poses a challenge for the cathode materials in protonic ceramic fuel cells (PCFCs). Most efforts are directed towards reducing the thermal expansion coefficient of Co-based materials, where often accompanies sacrifices in performance. In this article, bits of Co and Ni elements was dopped in BaPrO 3 material to adjust the electronical and proton transport ability. Triple-conducting oxide BaPr 1-x M x O 3-δ (M = Co/Ni, x = 0.1 and 0.2) was prepared as potential cathode for protonic ceramic fuel cells (PCFCs). The crystal structure, conductivity, proton uptake, proton transport, and electrochemical performance of were characterized in detail by experiment and first-principles calculations. BaPrO 3 , BaPr 0.9 Co 0.1 O 3-δ, and BaPr 0.8 Co 0.1 Ni 0.1 O 3-δ (BPCN) material present n-type conductive behavior while BaPr 0.9 Ni 0.1 O 3-δ material present p-type conductive behavior at high temperature. Among them, BPCN material presents the best performance for the highest electron and proton transport ability. The single cell with single BPCN material as cathode showed good performance with a peak power density of 1.42 W cm −2 and polarization resistance of only 0.07 Ω cm 2 at 700 °C, and there was no significant degradation within 100 h. The performance of Pr-based material is comparable to that of most Co and Fe-based materials, which gave a guide for the development of novel cathodes for PCFCs.