High current density reaching 1 A cm−2 for efficient oxygen evolution reaction (OER) was demonstrated by interactively optimizing electrolyte and electrode at non-extreme pH levels. Careful electrolyte assessment revealed that the state-of-the-art nickel-iron oxide electrocatalyst in alkaline solution maintained its high OER performance with a small Tafel slope in K-carbonate solution at pH 10.5 at 353 K. The OER performance was improved when Cu or Au was introduced into the FeOx-modified nanostructured Ni electrode as the third element during the preparation of electrode by electrodeposition. The resultant OER achieved 1 A cm−2 at 1.53 V vs. reversible hydrogen electrode (RHE) stably for 90 h, comparable to those in extreme alkaline conditions. Constant Tafel slopes, apparent activation energy, and the same signatures from operando X-ray absorption spectroscopy among these samples suggested that this improvement seems solely correlated with enhanced electrochemical surface area caused by adding the third element.
Bibliographical noteKAUST Repository Item: Exported on 2022-12-07
Acknowledged KAUST grant number(s): OSR #4191
Acknowledgements: A part of this work was supported by Asahi Kasei Corporation, UTokyo-KAUST collaborative research OSR #4191 “Towards Sustainable Production of H”, JSPS KAKENHI Grant Number 19KK0126, and the Mohammed bin Salman Center for Future Science and Technology for Saudi-Japan Vision 2030 at The University of Tokyo (MbSC2030). XAFS measurements were performed at the Spring-8 facility (2021B1168). We thank Y. Kono for the electrochemical test, which was conducted at the University of Tokyo. 2
This publication acknowledges KAUST support, but has no KAUST affiliated authors.
ASJC Scopus subject areas
- Environmental Chemistry
- Materials Science(all)
- Chemical Engineering(all)