Enhancing Perovskite Electrocatalysis through Strain Tuning of the Oxygen Deficiency
Enhancing Perovskite Electrocatalysis through Strain Tuning of the Oxygen Deficiency
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DOI：
10.1021/jacs.6b03520
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发表时间：
2016-06-15
影响因子：
15
通讯作者：
Lee, Ho Nyung
中科院分区：
文献类型：
--
作者：
Petrie, Jonathan R.;Jeen, Hyoungjeen;Lee, Ho Nyung
过渡金属氧化物中的氧空位促进了对能量储存和产生至关重要的催化作用。然而，在诸如金属空气电池和便携式燃料电池的装置中操作所需的较低温度下促进空位已被证明是难以实现的。在这里，我们使用钙钛矿基钴酸锶（SrCoOx）薄膜来表明外延应变是在与析氧反应一致的条件下操纵氧含量的有力工具，在钴酸盐通常被完全氧化的环境中产生越来越缺氧的状态：通过拉伸应变产生的额外的氧空位将钴酸盐对这一重要反应的催化活性提高了一个数量级以上，相当于贵金属催化剂，包括IrO2。我们的研究结果表明。这些氧化物可以决定氧的化学计量，而不依赖于环境条件，允许对在接近室温的催化中所必需的氧空位进行前所未有的控制。
Oxygen vacancies in transition-metal oxides facilitate catalysis critical for energy storage and generation. However, promoting vacancies at the lower temperatures required for operation in devices such as metal air batteries and portable fuel cells has proven elusive. Here we used thin films of perovskite-based strontium cobaltite (SrCoOx) to show that epitaxial strain is a powerful tool for manipulating the Oxygen content under condition consistent with the oxygen evolution reaction, yielding increasingly oxygen-deficient states in an environment where the cobaltite would normally be fully oxidized: The additional oxygen vacancies created through tensile strain enhance the cobaltite's catalytic activity toward this important reaction by over an order of magnitude, equaling that of precious-metal catalysts, including IrO2. Our findings demonstrate that strain in. these oxides can dictate the oxygen stoichiometry independent of ambient conditions, allowing unprecedented control over oxygen vacancies essential in catalysis near room temperature.