Rare-Earth-Modified NiS2 Improves OH Coverage for an Industrial Alkaline Water Electrolyzer

Wei Shen; Yao Zheng; Yang Hu; Jing Jin; Yichao Hou; Nan Zhang; Li An; Pinxian Xi; Chun-Hua Yan

doi:10.1021/jacs.3c11861

Rare-Earth-Modified NiS₂ Improves OH Coverage for an Industrial Alkaline Water Electrolyzer

J Am Chem Soc. 2024 Feb 28;146(8):5324-5332. doi: 10.1021/jacs.3c11861. Epub 2024 Feb 14.

Authors

Wei Shen¹, Yao Zheng², Yang Hu¹, Jing Jin¹, Yichao Hou¹, Nan Zhang¹, Li An¹, Pinxian Xi^{1

3}, Chun-Hua Yan^{1

4}

Affiliations

¹ State Key Laboratory of Applied Organic Chemistry, Frontiers Science Center for Rare Isotopes, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China.
² School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide, South Australia 5005, Australia.
³ State Key Laboratory of Baryunobo Rare Earth Resource Researches and Comprehensive Utilization, Baotou Research Institute of Rare Earths, Baotou 014030, China.
⁴ Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, PKU-HKU Joint Laboratory in Rare Earth Materials and Bioinorganic Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.

PMID: 38355103
DOI: 10.1021/jacs.3c11861

Abstract

The low coverage rate of anode OH adsorption under high current density conditions has become an important factor restricting the development of an industrial alkaline water electrolyzer (AWE). Here, we present our rare earth modification promotion strategy on using the rare earth oxygen-friendly interface to increase the OH coverage of the NiS₂ surface for efficient AWE anode catalysis. Density functional theory calculations predict that rare earths can enhance the coverage of surface OH, and the synthesis reaction mechanism is discussed in the synthesis process spectrum. Experimentally, by preparing a series of rare-earth-modified NiS₂, the relationship between OH coverage, active site density, and catalytic activity was established by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, time-resolved absorption spectra, and so on. The unique oxygenophilic properties of rare earths enhance OH coverage, thereby increasing the density of active sites for efficient catalysis. Furthermore, Eu₂O₃/NiS₂ was assembled into the AWE equipment and operated stably for over 240 h at a current density of 300 mA cm^-2 under industrial conditions of 80 °C and 30% KOH. Rare-earth-modified NiS₂ exhibits better catalytic activity than traditional non-noble metal anode catalysts Ni(OH)₂ and NiS₂, providing a new approach for rare earth promotion to solve the problem of low OH coverage in the AWE anode.