Promotion of oxygen reduction reaction on a double perovskite electrode by a water-induced surface modification
Promotion of oxygen reduction reaction on a double perovskite electrode by a water-induced surface modification
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DOI：
10.1039/d0ee03283b
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发表时间：
2021-03-01
影响因子：
32.5
通讯作者：
Liu, Meilin
中科院分区：
文献类型：
--
作者：
Kim, Jun Hyuk;Yoo, Seonyoung;Liu, Meilin
高效空气电极是可逆燃料电池的关键组成部分，用于能量储存和转换;然而，开发对水蒸气稳定的高效电极仍然是一个巨大的挑战。在这里，我们报告了一种空气电极，由双钙钛矿材料PrBa0.8Ca0.2Co2O5+ δ（PBCC）的骨干包覆纳米粒子（NPs）的BaCoO 3-δ（BCO），表现出显着的电催化活性的氧还原反应（ORR），同时保持良好的耐受水蒸气。当在750 ℃下暴露于含有3体积% H2O的湿空气的对称电池中进行测试时，电极在延长的时间段内显示出类似于0.03 Ω cm（2）的面积比电阻。性能的提高主要归因于分散在多孔PBCC电极表面的BCO纳米颗粒的电催化活性。此外，原位拉曼光谱用于探测反应中间体（例如，氧物种），因为电极的电化学性质在相同条件下表征。电极的表面化学和电化学行为之间的直接相关性对于深入了解燃料电池和电解槽中的电催化过程的机制至关重要。
Highly efficient air electrodes are a key component of reversible fuel cells for energy storage and conversion; however, the development of efficient electrodes that are stable against water vapor remains a grand challenge. Here we report an air-electrode, composed of double perovskite material PrBa0.8Ca0.2Co2O5+delta (PBCC) backbone coated with nanoparticles (NPs) of BaCoO3-delta (BCO), that exhibits remarkable electrocatalytic activity for oxygen reduction reaction (ORR) while maintaining excellent tolerance to water vapor. When tested in a symmetrical cell exposed to wet air with 3 vol% H2O at 750 degrees C, the electrode shows an area specific resistance of similar to 0.03 omega cm(2) in an extended period of time. The performance enhancement is attributed mainly to the electrocatalytic activity of the BCO NPs dispersed on the surface of the porous PBCC electrode. Moreover, in situ Raman spectroscopy is used to probe reaction intermediates (e.g., oxygen species) on electrode surfaces, as the electrochemical properties of the electrodes are characterized under the same conditions. The direct correlation between surface chemistry and electrochemical behavior of an electrode is vital to gaining insight into the mechanisms of the electrocatalytic processes in fuel cells and electrolysers.