Activation of the redox reaction is of prime importance for improving water-splitting reactions over transition-metal oxides with the crystal family of ABO₃ perovskites. Nowadays, much effort is being devoted to rationalizing the redox activities and searching for optimal compositions by changing the cations in A and B sites. Here, we show that different from general strategy, modification of the p-blocking centers through F-anion doping can provide opportunities to make a significant improvement in catalytic performance. Using this approach, we introduce an effective perovskite catalyst, La_0.5Ba_0.25Sr_0.25CoO_2.9–δF_0.1, for water splitting. Through ab initio modeling, we show that F-anions help uplift the O p band center and activate the redox capability of the lattice O for electrocatalysis, which suggests the potential mechanisms for designing new materials. Additionally, our findings move beyond the conventional charge transfer steps on transition-metal sites and emphasize the importance of the lattice O redox mediation for electrocatalysis.

氧化还原反应的活化对于改善具有ABO ₃钙钛矿晶体家族的过渡金属氧化物的水分解反应至关重要。如今，人们正在付出很大的努力来合理化氧化还原活性，并通过改变A和B位点的阳离子来寻找最佳的组成。在此，我们表明，与一般策略不同，通过F阴离子掺杂修饰p嵌段中心可以提供显着改善催化性能的机会。使用这种方法，我们引入了一种有效的钙钛矿催化剂La _0.5 Ba _0.25 Sr _0.25 CoO _2.9–δ F _0.1，用于水分解。通过从头开始建模，我们显示F阴离子有助于提升O  p带中心并激活晶格O的氧化还原能力以进行电催化，这表明了设计新材料的潜在机理。此外，我们的发现超出了过渡金属位点上常规电荷转移步骤的范围，并强调了晶格O氧化还原介导对电催化的重要性。