Surface reconstruction is an effective strategy to improve the OER performance of perovskites. However, understanding the reconstruction kinetics of perovskites and revealing real active sites for the OER remain elusive. Herein, we propose a secondary reconstruction strategy including phase transformation and electrochemical reconstruction to promote the electrocatalytic performance of perovskite. The as-prepared perovskite SrCoO_2.52 is first reconstructed into Ru atomically dispersed spinel Co₃O₄ (Ru_SA-Co₃O₄) by selective leaching, whose surface is further reconfigured into CoOOH through electrochemical reconstruction. The Ru_SA-Co₃O₄/CoOOH catalyst with massive oxygen vacancies exhibits an ultralow overpotential of 175 mV at 10 mA cm⁻² and maintains stability for up to 1000 h, which is the best perovskite-derived electrocatalyst to date. In situ XAS analysis and DFT calculations indicate that the valence states of Co species and isolated Ru single atoms are optimized and combined with –O ligands to form Co–O–O and Ru–O–O active sites. The secondary reconstruction can effectively regulate the electronic structure of the active metals thus providing the optimal adsorption energy for the reaction intermediates to promote the charge transfer in the OER process.

中文翻译：

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通过相变和电化学重构策略实现钙钛矿优异的析氧性能

表面重构是提高钙钛矿OER性能的有效策略。然而，了解钙钛矿的重建动力学并揭示 OER 的真正活性位点仍然难以捉摸。在此，我们提出了包括相变和电化学重构的二次重构策略，以提高钙钛矿的电催化性能。所制备的钙钛矿SrCoO _2.52首先通过选择性浸出重构为Ru原子分散的尖晶石Co ₃ O ₄ (Ru _SA -Co ₃ O ₄ )，其表面通过电化学重构进一步重构为CoOOH。具有大量氧空位的Ru _SA -Co ₃ O _{4 /CoOOH催化剂在10 mA cm} ^-2下表现出175 mV的超低过电势，并保持稳定性长达1000 h，是迄今为止最好的钙钛矿电催化剂。原位XAS分析和DFT计算表明Co物种和孤立的Ru单原子的价态被优化并与-O配体结合形成Co-O-O和Ru-O-O活性位点。二次重构可以有效调节活性金属的电子结构，从而为反应中间体提供最佳的吸附能，促进OER过程中的电荷转移。