Surface and bulk microstructures are critical factors in governing the catalytic activity of perovskite oxides for energy harvesting devices and chemical sensors. Herein, taking the La_0.5Ba_0.5CoO_3-δ as a reference, we found both the surface and bulk chemistry can be optimized through control of its cation non-stoichiometry. Specifically, Ba-deficiency can suppress the formation of the segregation layer, stabilize the crystal structures, decrease the oxide ions diffusion barrier, and bring a considerable improvement in catalytic activity and durability for the oxygen reaction reactions of the perovskite catalyst. These advantages can provide essential guidance for energy material designs in solid oxide fuel cells and other devices with oxygen reduction reaction process.

表面和整体微观结构是控制钙钛矿氧化物用于能量收集装置和化学传感器的催化活性的关键因素。此处，取La _0.5 Ba _0.5 CoO3 _-δ作为参考，我们发现可以通过控制其阳离子非化学计量来优化表面和本体化学。具体地，Ba缺乏可以抑制偏析层的形成，稳定晶体结构，降低氧化物离子的扩散势垒，并且对于钙钛矿型催化剂的氧反应反应具有显着的催化活性和耐久性的改善。这些优点可以为固体氧化物燃料电池和其他具有氧还原反应过程的设备中的能源材料设计提供必要的指导。