Dimensionally stable anodes (DSAs) are regarded to be optimized electrodes for electrochlorination owing to their excellent electrocatalytic activity for the chlorine evolution reaction (CER). However, in dilute chloride solutions, DSAs preferentially produce oxygen rather than chlorine because of their low overpotential for oxygen evolution reaction (OER). Considering the frequent use of electrochlorination in dilute conditions, the poor efficiency of DSAs severely limits their environmental and industrial applications. Therefore, the aim of this study is to improve the CER efficiency of IrO₂ in dilute chloride solutions with the addition of Fe₂O₃ as a co-catalyst which has a slow reaction rate of OER. In a dilute chloride solution of 1 mM NaCl, Ir_0.11Fe_0.25O_0.64 showed a far higher current efficiency for CER (28%) than that of IrO₂ (3%). Ir_0.11Fe_0.25O_0.64 also exhibited better current efficiency in NaCl solution of various concentrations (1 mM to 2 M) than that of IrO₂. This is attributed to the synergistic effect of Fe₂O₃ (slow OER rate) and IrO₂ (fast CER rate). Moreover, the long-term stability of Ir_0.11Fe_0.25O_0.64 was demonstrated with tap water electrolysis for 50 days. These results suggest that Ir_0.11Fe_0.25O_0.64 has great potential to expand the scope of application of the electrochlorination system, particularly in dilute solutions.

尺寸稳定的阳极 (DSA) 被认为是用于电氯化的优化电极，因为它们对析氯反应 (CER) 具有出色的电催化活性。然而，在稀氯化物溶液中，DSA 优先产生氧而不是氯，因为它们的析氧反应 (OER) 过电位较低。考虑到在稀释条件下频繁使用电氯化，DSA 的低效率严重限制了它们的环境和工业应用。因此，本研究的目的是提高 IrO ₂在稀氯化物溶液中的 CER 效率，加入 Fe ₂ O ₃作为 OER 反应速率缓慢的助催化剂。在 1 mM NaCl、Ir 的稀氯化物溶液中_0.11 Fe _0.25 O _0.64的 CER 电流效率 (28%) 远高于 IrO ₂ (3%)。Ir _0.11 Fe _0.25 O _0.64在各种浓度（1 mM 至2 M）的NaCl 溶液中也表现出比IrO ₂更好的电流效率。这归因于 Fe ₂ O ₃（慢 OER 速率）和 IrO ₂（快 CER 速率）的协同效应。此外，用自来水电解 50 天证明了Ir _0.11 Fe _0.25 O _0.64的长期稳定性。这些结果表明 Ir _0.11Fe _0.25 O _0.64具有扩大电解氯化系统应用范围的巨大潜力，特别是在稀溶液中。