Tackling activity-stability paradox of reconstructed NiIrOx electrocatalysts by bridged W-O moiety

• Published in: Nature communications Vol. 15; no. 1; pp. 10587 - 18
• Main Authors: Abdullah, Muhammad Imran, Fang, Yusheng, Wu, Xiaobing, Hu, Meiqi, Shao, Jing, Tao, Youkun, Wang, Haijiang
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 04.12.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 140/133; 147/135; 147/137; 147/143; 639/4077/909/4086; 639/638/161/886; 639/638/77/886; Acidic water; Acids; Adsorption; Catalysis; Crystal structure; Effectiveness; Electrocatalysts; Electrochemistry; Electrolysis; Humanities and Social Sciences; Intermediates; Metals; multidisciplinary; Oxidation; Oxygen evolution reactions; Paradoxes; Phase transitions; Science; Science (multidisciplinary); Stability; Valency
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-54987-4

One challenge remaining in the development of Ir-based electrocatalyst is the activity-stability paradox during acidic oxygen evolution reaction (OER), especially for the surface reconstructed IrO x catalyst with high efficiency. To address this, a phase selective Ir-based electrocatalyst is constructed by forming bridged W-O moiety in NiIrO x electrocatalyst. Through an electrochemical dealloying process, an nano-porous structure with surface-hydroxylated rutile NiWIrO x electrocatalyst is engineered via Ni as a sacrificial element. Despite low Ir content, NiWIrO x demonstrates a minimal overpotential of 180 mV for the OER at 10 mA·cm −2 . It maintains a stable 300 mA·cm −2 current density during an approximately 300 h OER at 1.8 V RHE and shows a stability number of 3.9 × 10 5 n oxygen  · n Ir −1 . The resulting W – O–Ir bridging motif proves pivotal for enhancing the efficacy of OER catalysis by facilitating deprotonation of OER intermediates and promoting a thermodynamically favorable dual-site adsorbent evolution mechanism. Besides, the phase selective insertion of W-O in NiIrO x enabling charge balance through the W-O-Ir bridging motif, effectively counteracting lattice oxygen loss by regulating Ir-O co-valency. One challenge remaining in the electrocatalysts for acidic water electrolysis is the activity-stability paradox. Here, the authors report a facile approach to tackle the challenge by introducing a bridged W-O moiety in NiIrO x electrocatalyst, enhancing the efficacy and stability simultaneously.