Abstract Oxygen evolution reaction (OER) is crucial for electrochemical water splitting. However, corrosive issues in the alkaline environment impede its applications. Here, we explore the corrosion-resistant multiphase Ni3Al-based intermetallic alloy (Ni3Al alloy) as self-supported OER catalysts for the first time. A two-step treatment, annealing at high-temperature followed by acid oxidation is performed to improve the catalytic activity. Further investigations demonstrate that the annealing process can tune the size of γ′ precipitates, which will modify the strain effects caused by γ/γ′ lattice mismatch to boost the OER activity. The oxidation of Ni during the acid pretreatment can facilitate the formation of active high-valent Ni sites during the OER process, and further enhance the OER performance. The optimized electrode exhibits a low overpotential of 280 mV at 10 mA cm−2, a small Tafel slope of 73.5 mV dec−1 and long-term stability of 180 h in 1 M KOH solution. The findings in this paper will inspire the exploration of high stability OER catalysts and the functional application of Ni3Al alloy.

中文翻译：

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应变调制 Ni3Al 合金促进析氧反应

摘要 析氧反应 (OER) 是电化学水分解的关键。然而，碱性环境中的腐蚀问题阻碍了其应用。在这里，我们首次探索了耐腐蚀的多相 Ni3Al 基金属间合金（Ni3Al 合金）作为自支撑 OER 催化剂。进行高温退火和酸氧化两步处理以提高催化活性。进一步的研究表明，退火过程可以调整 γ' 沉淀物的尺寸，这将改变由 γ/γ' 晶格失配引起的应变效应，从而提高 OER 活性。酸预处理过程中Ni的氧化可以促进OER过程中活性高价Ni位点的形成，进一步提高OER性能。优化后的电极在 10 mA cm-2 下表现出 280 mV 的低过电位、73.5 mV dec-1 的小塔菲尔斜率和在 1 M KOH 溶液中 180 小时的长期稳定性。本文的研究结果将启发高稳定性OER催化剂的探索和Ni3Al合金的功能应用。