TY  - JOUR
AU  - Kante, Mohana V.
AU  - Weber, Moritz L.
AU  - Ni, Shu
AU  - van den Bosch, Iris C. G.
AU  - van der Minne, Emma
AU  - Heymann, Lisa
AU  - Falling, Lorenz J.
AU  - Gauquelin, Nicolas
AU  - Tsvetanova, Martina
AU  - Cunha, Daniel M.
AU  - Koster, Gertjan
AU  - Gunkel, Felix
AU  - Nemšák, Slavomír
AU  - Hahn, Horst
AU  - Velasco Estrada, Leonardo
AU  - Baeumer, Christoph
TI  - A High-Entropy Oxide as High-Activity Electrocatalyst for Water Oxidation
JO  - ACS nano
VL  - 17
IS  - 6
SN  - 1936-0851
CY  - Washington, DC
PB  - Soc.
M1  - FZJ-2023-01482
SP  - 5329–5339
PY  - 2023
AB  - 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.
LB  - PUB:(DE-HGF)16
C6  - 36913300
UR  - <Go to ISI:>//WOS:000953440900001
DO  - DOI:10.1021/acsnano.2c08096
UR  - https://juser.fz-juelich.de/record/1005453
ER  -