The oxygen evolution reaction (OER) is an electrochemical bottleneck half-reaction in some important energy conversion systems (e.g., water splitting), which is traditionally mediated by iridium oxides in acidic environment. Perovskite-structured Ir-containing oxides (e.g., SrIrO₃) are a family of striking electrocatalysts due to their high specific activity, but this excellent quality is difficultly transferred to a nano-electrocatalyst with large active surface and good structural stability. Here, we present a synthesis method that produces a 2D ultrathin {001}-faceted SrIrO₃ perovskite (2D-SIO) with a thickness of ∼5 nm and high surface area (57.6 m² g⁻¹). We show that 2D-SIO can serve as a highly active and stable electrocatalytic nanomaterial for OER under acidic conditions. This perovskite nanomaterial produces 10 mA cm⁻² current density at a low overpotential (η, 243 mV), and maintains its catalytic activity after 5000 continuous cyclic measurements. Besides ultrathin structure and large surface area, the exposed {001} facets are found to be the most crucial and unique structural factor for achieving high catalytic activity and structural stability. Our joint experimental and theoretical results demonstrate that these advantageous microstructural features of 2D-SIO endow it with a strong capability to generate the key O* intermediates, and thereby facilitate O–O bond formation and the OER.

析氧反应（OER）是一些重要的能量转换系统（如水分解）中的电化学瓶颈半反应，传统上由酸性环境中的氧化铱介导。钙钛矿结构的含 Ir 氧化物（例如 SrIrO ₃）由于其高比活性而成为一类引人注目的电催化剂，但这种优异的品质很难转移到具有大活性表面和良好结构稳定性的纳米电催化剂上。这里，我们提出，其产生2D超薄{001} -faceted SrIrO的合成方法₃的厚度约为5纳米和高表面积（57.6米钙钛矿（2D-SIO）²克^-1）。我们表明，2D-SIO 在酸性条件下可以作为 OER 的高活性和稳定的电催化纳米材料。这种钙钛矿纳米材料在低过电位 ( η , 243 mV) 下产生 10 mA cm ^-2电流密度，并在 5000 次连续循环测量后保持其催化活性。除了超薄结构和大表面积外，暴露的{001}面被发现是实现高催化活性和结构稳定性的最关键和独特的结构因素。我们的联合实验和理论结果表明，2D-SIO 的这些有利的微观结构特征赋予其生成关键 O* 中间体的强大能力，从而促进 O-O 键的形成和 OER。