Engineering electrocatalytic activity in nanosized perovskite cobaltite through surface spin-state transition.
Engineering electrocatalytic activity in nanosized perovskite cobaltite through surface spin-state transition.
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通过表面自旋态转变设计纳米钙钛矿钴矿的电催化活性
DOI：
10.1038/ncomms11510
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发表时间：
2016-05-17
影响因子：
16.6
通讯作者：
Zeng J
中科院分区：
文献类型：
--
作者：
Zhou S;Miao X;Zhao X;Ma C;Qiu Y;Hu Z;Zhao J;Shi L;Zeng J
电催化剂的活性对其电子结构表现出强烈的依赖性。具体而言，对于钙钛矿氧化物，Shao-Horn 及其同事报道了析氧反应活性与过渡金属离子的自轨道占据之间的相关性，这为高活性催化剂的设计提供了指导。在这里，我们展示了一种简单的方法来设计钙钛矿钴矿 LaCoO3 的填充，以提高析氧反应活性。通过将颗粒尺寸减小至~80纳米，钴离子的填充量成功地从单一增加到接近Shao-Horn原理所期望的最佳构型1.2。因此，与最近报道的具有~1.2构型的氧化钴相比，活性显着增强。这种增强归因于纳米颗粒表面钴离子从低自旋态到高自旋态的自旋态转变的出现，导致更多的活性位点和更高的反应性。
The activity of electrocatalysts exhibits a strongly dependence on their electronic structures. Specifically, for perovskite oxides, Shao-Horn and co-workers have reported a correlation between the oxygen evolution reaction activity and theegorbital occupation of transition-metal ions, which provides guidelines for the design of highly active catalysts. Here we demonstrate a facile method to engineer theegfilling of perovskite cobaltite LaCoO3for improving the oxygen evolution reaction activity. By reducing the particle size to ∼80 nm, theegfilling of cobalt ions is successfully increased from unity to near the optimal configuration of 1.2 expected by Shao-Horn’s principle. Consequently, the activity is significantly enhanced, comparable to those of recently reported cobalt oxides witheg∼1.2configurations. This enhancement is ascribed to the emergence of spin-state transition from low-spin to high-spin states for cobalt ions at the surface of the nanoparticles, leading to more active sites with increased reactivity.