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Haase, Felix Thomas ; Rabe, Anna ; Schmidt, Franz-Philipp ; Herzog, Antonia ; Jeon, Hyo Sang ; Frandsen, Wiebke ; Narangoda, Praveen Vidusha ; Spanos, Ioannis ; Ortega, Klaus Friedel ; Timoshenko, Janis ; Lunkenbein, Thomas ; Behrens, Malte ; Bergmann, Arno ; Schlögl, Robert ; Roldán Cuenya, Beatriz:
Role of Nanoscale Inhomogeneities in Co₂FeO₄ Catalysts during the Oxygen Evolution Reaction.
In: Journal of the American Chemical Society.
Bd. 144
(2022)
Heft 27
.
- S. 12007-12019.
ISSN 1520-5126
DOI: https://doi.org/10.1021/jacs.2c00850
Abstract
Spinel-type catalysts are promising anode materials for the alkaline oxygen evolution reaction (OER), exhibiting low overpotentials and providing long-term stability. In this study, we compared two structurally equal Co2FeO4 spinels with nominally identical stoichiometry and substantially different OER activities. In particular, one of the samples, characterized by a metastable precatalyst state, was found to quickly achieve its steady-state optimum operation, while the other, which was initially closer to the ideal crystallographic spinel structure, never reached such a state and required 168 mV higher potential to achieve 1 mA/cm2. In addition, the enhanced OER activity was accompanied by a larger resistance to corrosion. More specifically, using various ex situ, quasi in situ, and operando methods, we could identify a correlation between the catalytic activity and compositional inhomogeneities resulting in an X-ray amorphous Co2+-rich minority phase linking the crystalline spinel domains in the as-prepared state. Operando X-ray absorption spectroscopy revealed that these Co2+-rich domains transform during OER to structurally different Co3+-rich domains. These domains appear to be crucial for enhancing OER kinetics while exhibiting distinctly different redox properties. Our work emphasizes the necessity of the operando methodology to gain fundamental insight into the activity-determining properties of OER catalysts and presents a promising catalyst concept in which a stable, crystalline structure hosts the disordered and active catalyst phase.
Weitere Angaben
| Publikationsform: | Artikel in einer Zeitschrift |
|---|---|
| Begutachteter Beitrag: | Ja |
| Zusätzliche Informationen: | WOS:000823278700001 |
| Institutionen der Universität: | Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften > Fachgruppe Chemie |
| Titel an der UBT entstanden: | Nein |
| Themengebiete aus DDC: | 500 Naturwissenschaften und Mathematik > 540 Chemie |
| Eingestellt am: | 12 Jun 2025 10:53 |
| Letzte Änderung: | 12 Jun 2025 10:53 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/93678 |