High entropy promoted active site in layered double hydroxide for ultra-stable oxygen evolution reaction electrocatalyst

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 466; p. 143352
• Main Authors: Nguyen, Thi Xuyen, Tsai, Chia-Chien, Nguyen, Van Thanh, Huang, Yan-Jia, Su, Yen-Hsun, Li, Siang-Yun, Xie, Rui-Kun, Lin, Yu-Jung, Lee, Jyh-Fu, Ting, Jyh-Ming
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.06.2023
• Subjects: High-entropy; Layer double hydroxide; Oxygen evolution reaction; Layer double hydroxide; High-entropy; Oxygen evolution reaction
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2023.143352

[Display omitted] •Novel high entropy layered double hydroxide supported on Ni foam demonstrates excellent OER performance.•Structural evolution of the catalyst during OER has been investigated using in situ Raman characterization.•γ-NiOOH with high valence state of Ni3.6+ serves as the catalytic active species to promote the OER activity.•Effective electronic structure modulation due to compositional tuning has been examined using XPS and XAS.•Density functional theory calculation supports the experimental data. In this study, high entropy layered double hydroxide (LDH) grown on nickel foam using a simple hydrothermal method is reported. The high entropy LDH consisting of five different non-noble transition metals of Fe, Ni, Co, Mn, and Cr (denoted as FeNiCoMnCr) exhibits an excellent OER activity in alkaline condition with a low overpotential of 218 mV at a current density of 50 mA cm−2. It is superior to the binary, ternary, and quaternary-metal LDHs. We demonstrate that the high entropy FeNiCoMnCr LDH possesses ultra-stable electrochemical stability at a high current density of 400 mA cm−2 for 600 h, which is the best stability of all the reported high entropy material electrocatalysts so far. The interaction among the multi-metal components along with the resulting electronic structure modulation facilitates the formation of highly-active γ-NiOOH species, significantly boosting catalytic activity; while the high entropy induced phase stability contributes to the superior durability.