Journal Article

FZJ-2023-01482

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png A High-Entropy Oxide as High-Activity Electrocatalyst for Water Oxidation

Kante, M. V. ; Weber, M. L.FZJ* ; Ni, S. ; van den Bosch, I. C. G. ; van der Minne, E. ; Heymann, L.FZJ* ; Falling, L. J. ; Gauquelin, N. ; Tsvetanova, M. ; Cunha, D. M. ; Koster, G. ; Gunkel, F.FZJ* ; Nemšák, S. ; Hahn, H. ; Velasco Estrada, L. ; Baeumer, C. (Corresponding author)FZJ*

2023
Soc. Washington, DC

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Please use a persistent id in citations: http://hdl.handle.net/2128/34207  doi:10.1021/acsnano.2c08096

Abstract: High-entropy materials are an emerging pathway in the development of high-activity (electro)catalysts because of the inherent tunability and coexistence of multiple potential active sites, which may lead to earth-abundant catalyst materials for energy-efficient electrochemical energy storage. In this report, we identify how the multication composition in high-entropy perovskite oxides (HEO) contributes to high catalytic activity for the oxygen evolution reaction (OER), i.e., the key kinetically limiting half-reaction in several electrochemical energy conversion technologies, including green hydrogen generation. We compare the activity of the (001) facet of LaCr0.2Mn0.2Fe0.2Co0.2Ni0.2O3-δ with the parent compounds (single B-site in the ABO3 perovskite). While the single B-site perovskites roughly follow the expected volcano-type activity trends, the HEO clearly outperforms all of its parent compounds with 17 to 680 times higher currents at a fixed overpotential. As all samples were grown as an epitaxial layer, our results indicate an intrinsic composition–function relationship, avoiding the effects of complex geometries or unknown surface composition. In-depth X-ray photoemission studies reveal a synergistic effect of simultaneous oxidation and reduction of different transition metal cations during the adsorption of reaction intermediates. The surprisingly high OER activity demonstrates that HEOs are a highly attractive, earth-abundant material class for high-activity OER electrocatalysts, possibly allowing the activity to be fine-tuned beyond the scaling limits of mono- or bimetallic oxides.

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Contributing Institute(s):

1. Elektronische Materialien (PGI-7)
2. JARA-FIT (JARA-FIT)

Research Program(s):

1. 5233 - Memristive Materials and Devices (POF4-523) (POF4-523)

Appears in the scientific report 2023

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Essential Science Indicators ; IF >= 15 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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