Sha Qihao, Gao Tianshu, Yan Li, Hung Wei-Hsuan, Chiang Ching-Yu, Zhou Daojin, Liu Bin, Kuang Yun, Sun Xiaoming
State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, P. R. China.
School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637459, Singapore.
J Am Chem Soc. 2025 Jun 18;147(24):20716-20724. doi: 10.1021/jacs.5c04206. Epub 2025 Jun 4.
Efficient seawater oxidation reaction is crucial for advancing hydrogen fuel production. Developing highly efficient oxygen evolution reaction (OER) catalysts that follow the lattice oxygen mechanism (LOM) can effectively mitigate undesirable chloride oxidation side reactions in seawater electrolysis and reduce energy consumption. Herein, we propose a Cl-mediation strategy that is able to shift the OER mechanism from the adsorbate evolution mechanism (AEM) to LOM on nickel sites. By loading highly dispersed Ir onto Ni-based precursors (e.g., NiSe, Ni(OH), NiS and NiSOH), we exploit the robust coordination interaction between Ir and Cl in seawater to establish a Cl-Ir-O-Ni electron-withdrawing chain from Ni to Cl, which strengthens Ni-O covalency during the OER, thereby activating lattice oxygen around the Ni sites in seawater. As a result, the Cl-modified Ir/NiOOH-Se@Cl catalyst requires an overpotential of only 313 mV to achieve an OER current density of 0.5 A cm, demonstrating a reduction of 147 mV compared to that in alkaline condition (Ir/NiOOH-Se@OH) and also maintaining stable operation at 0.5 A cm for 500 h. Our work provides a novel and intriguing concept for regulating local lattice oxygen activity toward developing highly efficient oxygen electrocatalysts for clean energy productions.
高效的海水氧化反应对于推动氢燃料生产至关重要。开发遵循晶格氧机制（LOM）的高效析氧反应（OER）催化剂能够有效减轻海水电解中不良的氯氧化副反应并降低能耗。在此，我们提出一种Cl介导策略，该策略能够使OER机制在镍位点上从吸附质演化机制（AEM）转变为LOM。通过将高度分散的Ir负载到镍基前驱体（如NiSe、Ni(OH)、NiS和NiSOH）上，我们利用海水中Ir与Cl之间强大的配位相互作用，从Ni到Cl建立一条Cl-Ir-O-Ni吸电子链，这在OER过程中增强了Ni-O共价性，从而激活海水中镍位点周围的晶格氧。结果，Cl修饰的Ir/NiOOH-Se@Cl催化剂仅需313 mV的过电位即可实现0.5 A cm²的OER电流密度，与碱性条件下（Ir/NiOOH-Se@OH）相比降低了147 mV，并且在0.5 A cm²下保持500 h的稳定运行。我们的工作为调节局部晶格氧活性以开发用于清洁能源生产的高效氧电催化剂提供了一个新颖且有趣的概念。
