State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, 130012, Changchun, People's Republic of China.
College of Materials Science and Engineering, Jilin University, 130022, Changchun, People's Republic of China.
Nat Commun. 2018 Dec 7;9(1):5236. doi: 10.1038/s41467-018-07678-w.
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 SrIrO perovskite (6H-SrIrO) as a highly active electrocatalyst with good structural and catalytic stability for OER in acid. 6H-SrIrO contains 27.1 wt% less iridium than IrO, but its iridium mass activity is about 7 times higher than IrO, a benchmark electrocatalyst for the acidic OER. 6H-SrIrO 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-SrIrO thanks to the weakened surface Ir-O binding that facilitates the potential-determining step involved in the OER (i.e., O* + HO → HOO* + H + e).
质子交换膜水电解的广泛应用需要开发更高效的电催化剂，其中包含减少昂贵的铱用量，用于氧气析出反应（OER）。在这里，我们发现 6H 相 SrIrO 钙钛矿（6H-SrIrO）是一种在酸性条件下具有良好结构和催化稳定性的 OER 高活性电催化剂。6H-SrIrO 中的铱含量比 IrO 少 27.1wt%，但其质量活性约为 IrO 的 7 倍，IrO 是酸性 OER 的基准电催化剂。基于最高的铱质量活性，6H-SrIrO 是最近报道的基于铱的氧化物中 OER 最活跃的催化材料。理论计算表明，面共享八面体二聚体的存在主要是由于表面 Ir-O 键合的减弱，从而促进了 OER 中涉及的决定电位步骤（即 O* + HO → HOO* + H + e），这使得 6H-SrIrO 具有优异的活性。
