Robust catalytic materials with high activity and stability play important roles in energy conversion and storage devices such as protonic ceramic fuel cells (PCFCs), in which a favourable cathode should possess high oxygen ion, proton and electron triple conductivities, and superior surface oxygen exchange kinetics. Herein, a thermal-driven self-construction phenomenon in cation-nonstoichiometric Ba_1+xGd_1-xCo₂O_6-δ is reported, accordingly developing a new type of nanocomposite, that is, double perovskite BaGdCo₂O_6-δ (DP-BGCO) anchored by perovskite-derived BaCoO_3-δ (P-D-BCO) nanoparticles, which, used as the cathode of PCFCs, demonstrates low area-specific resistances of 0.053 and 0.026 ohm cm⁻² respectively at 650 and 700 °C over BaZr_0.3Ce_0.5Y_0.1Yb_0.1O_3-δ protonic electrolyte and attractive peak power densities of 0.87 (650 °C) and 1.15 W cm⁻² (700 °C) with outstanding stability, much superior to the similar cell with single-phase BCO or BGCO cathodes. The synergy between the two components brings the outstanding performance with the mixed oxygen ion and electronic conducting perovskite-derived oxide showing superior catalytic activity for oxygen reduction reaction while the double perovskite provides good bulk protonic conductivity to enlarge reaction sites. Such selective self-construction, well manipulated through the A-site cation stoichiometry engineering, provides a facile way for developing new high-performance electrocatalysts with broad application potential.

中文翻译：

---

钙钛矿衍生氧化物在双钙钛矿表面上的自发生长以增强质子陶瓷燃料电池的阴极性能


具有高活性和稳定性的鲁棒催化材料在质子陶瓷燃料电池（PCFC）等能量转换和存储装置中发挥着重要作用，其中有利的阴极应具有高氧离子、质子和电子三重电导率以及优异的表面氧交换动力学。本文报道了阳离子非化学计量 Ba _1+x Gd _1-x Co ₂ O _6-δ 中热驱动的自构建现象，相应地开发了一种新型纳米复合材料，即由钙钛矿衍生的 BaCoO _3-δ 锚定的双钙钛矿 BaGdCo ₂ O _6-δ (DP-BGCO) (P-D-BCO) ) 纳米粒子，用作 PCFC 的阴极，在 650 °C 和 700 °C 时表现出比 BaZr _0.3 Ce _0.5 Y _0.1 Yb _0.1 O _3-δ 质子电解质，峰值功率密度为 0.87 (650 °C) 和 1.15 W cm ⁻² (700 °C) 具有出色的稳定性，远远优于具有单相 BCO 或 BGCO 阴极的类似电池。两种成分之间的协同作用带来了出色的性能，混合氧离子和电子导电钙钛矿衍生氧化物对氧还原反应表现出优异的催化活性，而双钙钛矿则提供良好的本体质子传导性以扩大反应位点。这种选择性的自构建，通过A位阳离子化学计量工程得到很好的操纵，为开发具有广泛应用潜力的新型高性能电催化剂提供了一种简便的方法。