Lattice Cl <sup>−</sup> reconstruction in a ternary hydroxychloride pre-electrocatalyst for efficient saline water oxidation
Mingyang Wei, Jing Wang, Xiaoqing Ma, Yuzhe Cao, Xiaolei Yuan, Yang Li-xia, Zhao Cai
Abstract
The development of efficient electrocatalysts for saline water oxidation (SWO) is imperative for advancing seawater splitting technology to produce green hydrogen. In this work, we reported a NiFeCo hydroxychloride pre-electrocatalyst with the merits of high surface area and anti-corrosion, which exhibited both active and stable SWO performance. The lattice Cl<sup>- </sup>of NiFeCo hydroxychloride was leached during catalysis, leading to the 35.4% enlarged surface area of the catalysts, which showed a SWO overpotential of 369 mV at 100 mA cm<sup>-2</sup>, 105 mV and 154 mV lower than the NiFeCo layered double hydroxide and commercial RuO<sub>2</sub> catalysts, respectively. Moreover, <em>in-situ </em>Raman demonstrated the incorporation of electrolyte Cl<sup>-</sup> to the lattice of the catalysts and the re-formation of Co-Cl bonds, which resulted in the enhanced anti-corrosion performance and high electrocatalytic stability for 100 h. These results provide a convincing demonstration of the reconstruction of ternary hydroxychloride pre-electrocatalysts for efficient seawater splitting hydrogen production.