Alkali Cation Interactions with Superoxide Intermediates during the Oxygen Evolution Reaction on Ni<sub>1–<i>x</i></sub>Fe<sub><i>x</i></sub>OOH
Alkali-cation-dependent kinetics have been widely observed for the oxygen evolution reaction (OER); however, reported trends and the underlying mechanism lack consensus. Herein, the OER activity on Ni1–xFexOOH was determined to follow the order Cs+ > K+, Na+ > Li+. Coupling operando surface-enhanced Raman spectroscopy (SERS) with X2O (X = H or D) and H2YO (Y = 16 or 18) isotope labeling revealed scavenging of superoxide (O–O–) intermediates in the presence of Li+ leading to the formation of Li2CO3, resulting in a modified reaction path and subgrade activity. Ni1–xFexOOH catalytic films revealed stable performance during 18 days of anodic polarization in 1 M XOH at 60 °C. Conversely, severe degradation was observed in 6 M XOH due to delamination of the catalytic coating as well as loss of active sites and formation of unwanted FeOOH and NiOx moieties, regardless of alkali metal cation type.
Authors
- Christodoulos Chatzichristodoulou (ORCID: https://orcid.org/0000-0001-6499-5914)
- Mike Tebyetekerwa (ORCID: https://orcid.org/0000-0002-4243-6043)
- Pradipkumar Manubhai Leuaa (ORCID: https://orcid.org/0000-0002-3475-9184)
- Sarmad Iqbal (ORCID: https://orcid.org/0000-0002-8798-2697)
- Laurence J. Hardwick (ORCID: https://orcid.org/0000-0001-8796-685X)
- Fabian Luca Buchauer (ORCID: https://orcid.org/0009-0004-5947-1269)
- Umer Javed (ORCID: https://orcid.org/0000-0001-6806-3938)
Institutions
- University of Liverpool (GB)
- The University of Queensland (AU)
- Technical University of Denmark (DK)
Publication Details
- Journal
- ACS Energy Letters
- Published
- 2025-06-24
- DOI
- https://doi.org/10.1021/acsenergylett.5c01481
- Primary Topic
- Electrocatalysts for Energy Conversion
- Type
- article
- Field-Weighted Citation Impact
- 0.00