A substantial amount of interest has been focused on ABO₃-type perovskite oxides over the past decade as oxygen electrocatalysts. Despite many studies on various compositions, the correlation between the structure of the oxygen octahedra and electrocatalytic property has been overlooked, and there accordingly have been a very limited number of attempts regarding control of atomistic structure. Utilizing epitaxial LnNiO₃ (Ln = La, Pr, Nd) thin films, here we demonstrate that simple electrochemical exchange of Fe in the surface region with several-unit-cell thickness is notably effective to boost the catalytic activity for the oxygen evolution reaction by different orders of magnitude. Furthermore, we directly establish that strong distortion of oxygen octahedra at the angstrom scale is readily induced during the Fe exchange, and that this structural perturbation permits easier charge transfer. The findings suggest that structural alteration can be an efficient approach to achieve exceptional electrocatalysis in crystalline oxides.

在过去的十年中，大量关注集中在AB O ₃型钙钛矿氧化物作为氧电催化剂。尽管对各种组成进行了许多研究，但是氧八面体的结构与电催化性能之间的相关性却被忽略了，因此，关于控制原子结构的尝试非常有限。利用外延Ln NiO ₃（Ln = La，Pr，Nd）薄膜，在这里我们证明表面区域中具有几个单位电池厚度的Fe的简单电化学交换显着有效地提高了不同数量级的氧释放反应的催化活性。此外，我们直接建立了在Fe交换过程中容易诱发八面体氧八面体的强烈变形的现象，并且这种结构扰动使电荷转移更加容易。研究结果表明，结构改变可能是在结晶氧化物中实现优异电催化的有效方法。