@article{455d4b83b6ce45c9a56af793cca72780,
title = "A High-Entropy Oxide as High-Activity Electrocatalyst for Water Oxidation",
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.",
keywords = "Green hydrogen, High-entropy oxides, Oxygen evolution reaction (OER), Perovskite oxide catalysts, Scaling reactions, Water electrolysis, UT-Hybrid-D",
author = "Kante, {Mohana V.} and Weber, {Moritz L.} and Shu Ni and {van den Bosch}, {Iris C.G.} and {van der Minne}, Emma and Lisa Heymann and Falling, {Lorenz J.} and Nicolas Gauquelin and Martina Tsvetanova and Cunha, {Daniel M.} and Gertjan Koster and Felix Gunkel and Slavom{\'i}r Nem{\v s}{\'a}k and Horst Hahn and {Velasco Estrada}, Leonardo and Christoph Baeumer",
note = "Funding Information: Support from the University of Twente in the framework of the tenure track start-up package is gratefully acknowledged. I.C.G.B. and C.B. received cofunding from the European Union (ERC, 101040669-Interfaces at Work). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them. L.V., M.V.K., and H.H. acknowledge financial support by the Deutsche Forschungsgemeinschaft (DFG) under Grant Nos. HA 1344/45-1 and VE 1111/1-1 and project identifier number 424789449. L.J.F. acknowledges support from the Alexander von Humboldt Foundation, Bonn, Germany. This publication is part of the project “High entropy oxide electrocatalysts” (with project number KICH1.ED04.20.003) of the research program ECCM KICkstart DE-NL which is (partly) financed by the Dutch Research Council (NWO). Funding Information: The authors thank Qiyang Lu, Monica Morales Masis, and Marco Altomare for critical discussion, Minh Nguyen, Shreyas Harsha, and Tursun Abudukade for help in sample fabrication, and Karin van den Nieuwenhuijzen and Ellen Kiens for XRD measurements. We thank Melissa Goodwin for FIB sample preparation. L.V. thanks the Karlsruhe Nano Micro Facility (KNMF, Germany) and Prof. Christian K{\"u}bel for providing access to TEM at KIT. This research used beamline 9.3.2 of the Advanced Light Source, a U.S. DOE Office of Science User Facility under Contract No. DE-AC02-05CH11231. M.L.W. was supported in part by an ALS Collaborative Postdoctoral Fellowship. Funding Information: The authors thank Qiyang Lu, Monica Morales Masis, and Marco Altomare for critical discussion, Minh Nguyen, Shreyas Harsha, and Tursun Abudukade for help in sample fabrication, and Karin van den Nieuwenhuijzen and Ellen Kiens for XRD measurements. We thank Melissa Goodwin for FIB sample preparation. L.V. thanks the Karlsruhe Nano Micro Facility (KNMF, Germany) and Prof. Christian K{\"u}bel for providing access to TEM at KIT. This research used beamline 9.3.2 of the Advanced Light Source, a U.S. DOE Office of Science User Facility under Contract No. DE-AC02-05CH11231. M.L.W. was supported in part by an ALS Collaborative Postdoctoral Fellowship. Support from the University of Twente in the framework of the tenure track start-up package is gratefully acknowledged. I.C.G.B. and C.B. received cofunding from the European Union (ERC, 101040669-Interfaces at Work). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them. L.V., M.V.K., and H.H. acknowledge financial support by the Deutsche Forschungsgemeinschaft (DFG) under Grant Nos. HA 1344/45-1 and VE 1111/1-1 and project identifier number 424789449. L.J.F. acknowledges support from the Alexander von Humboldt Foundation, Bonn, Germany. This publication is part of the project “High entropy oxide electrocatalysts” (with project number KICH1.ED04.20.003) of the research program ECCM KICkstart DE-NL which is (partly) financed by the Dutch Research Council (NWO). Publisher Copyright: {\textcopyright} 2023 The Authors. Published by American Chemical Society.",
year = "2023",
month = mar,
day = "28",
doi = "10.1021/acsnano.2c08096",
language = "English",
volume = "17",
pages = "5329--5339",
journal = "ACS nano",
issn = "1936-0851",
publisher = "American Chemical Society",
number = "6",
}