Engineered Nickel-Iron Nitride Electrocatalyst for Industrial-Scale Seawater Hydrogen Production.

Hu, Huashuai; Wang, Xunlu; Zhang, Zhaorui; Liu, Jiahao; Yan, Xiaohui; Wang, Xiaoli; Wang, Jiacheng; Attfield, J Paul et al. · Adv Mater · 2025

basic_science · Level V

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Abstract

Seawater electrolysis under alkaline conditions is a crucial technology for sustainable hydrogen production. However, achieving the long-term stability of the electrocatalyst remains a significant challenge. In this study, it is demonstrated that surface reconstruction of a transition metal nitride (TMN) can be used to develop a highly stable oxygen evolution reaction (OER) electrocatalyst. Rapid introduction of phosphate groups (PO<sub>4</sub> <sup>3-</sup>) accelerates the in situ surface reconstruction of Ni<sub>3</sub>FeN, generating a catalyst, with a conductive nitride core and Cl<sup>-</sup>-resistant hydroxide shell that demonstrates outstanding performance, maintaining stability for over 2500 h at 1 A cm<sup>-2</sup> current density in alkaline seawater. In situ characterization and density functional theory (DFT) calculations reveal the dynamic evolution of active sites, providing insights into the mechanisms driving long-term stability. This work not only introduces an efficient approach to TMN-based catalyst design but also advances the development of durable electrocatalysts for industrial-scale seawater hydrogen production.