The widespread use of proton exchange membrane water electrolysis requires the development of more efficient electrocatalysts containing reduced amounts of expensive iridium for the oxygen evolution reaction (OER). Here we present the identification of 6H-phase SrIrO₃ perovskite (6H-SrIrO₃) as a highly active electrocatalyst with good structural and catalytic stability for OER in acid. 6H-SrIrO₃ contains 27.1 wt% less iridium than IrO₂, but its iridium mass activity is about 7 times higher than IrO₂, a benchmark electrocatalyst for the acidic OER. 6H-SrIrO₃ is the most active catalytic material for OER among the iridium-based oxides reported recently, based on its highest iridium mass activity. Theoretical calculations indicate that the existence of face-sharing octahedral dimers is mainly responsible for the superior activity of 6H-SrIrO₃ thanks to the weakened surface Ir-O binding that facilitates the potential-determining step involved in the OER (i.e., O* + H₂O → HOO* + H⁺ + e_¯).

中文翻译：

---

钙钛矿与面共享的IrO6八面体二聚体可在酸中有效地释放氧气。

质子交换膜水电解的广泛使用要求开发更有效的电催化剂，其中包含减少量的用于氧析出反应（OER）的昂贵的铱。在这里，我们提出了6H相SrIrO ₃钙钛矿（6H-SrIrO ₃）的鉴定，它是一种高活性的电催化剂，对酸中的OER具有良好的结构和催化稳定性。6H-SrIrO _3的铱含量比IrO ₂少27.1 wt％，但其铱的质量活性比酸性OER的基准电催化剂IrO ₂高约7倍。6H-SrOrO ₃由于其最高的铱质量活度，它是最近报道的铱基氧化物中OER活性最高的催化材料。理论计算表明，面共享八面体二聚体的存在主要归因于6H-SrIrO ₃的出色活性，这归因于表面Ir-O结合力的减弱，这促进了OER中涉及的电势确定步骤（即O * + ħ ₂ O→HOO * + H ⁺ + E _＆OverBar; ）。