TY - JOUR

T1 - (Ni1-xFex)OOH Binary Nanoparticles in as-Prepared and Purified KOH Electrolyte Solutions for Water Splitting

AU - Wang, Baiyu

AU - Schlegel, Nicolas

AU - Aalling-Frederiksen, Olivia

AU - Berner, Etienne

AU - Zhang, Damin

AU - Pittkowski, Rebecca K.

AU - Jensen, Kirsten M.Ø.

AU - Arenz, Matthias

N1 - Funding Information: We acknowledge support from the Swiss National Science Foundation (SNSF) project No. 200021_184742 and the Danish National Research Foundation Center for High Entropy Alloy Catalysis (DNRF 149). We are grateful to the Villum Foundation for the financial support through a Villum Young Investigator grant (No. 0015416). We furthermore thank DANSCATT (supported by the Danish Agency for Science and Higher Education) for the support. Funding from the Danish Ministry of Higher Education and Science through the SMART Lighthouse is gratefully acknowledged. We acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Parts of this research were carried out at PETRA III, and we would like to thank Henrik Jeppesen for assistance in using the beamline P02.1. Beamtime was allocated by an In-House contingent. The authors acknowledge access to the Microscopy Imaging Center (MIC) facilities of the University of Bern. Publisher Copyright: © 2024 American Chemical Society.

PY - 2024

Y1 - 2024

N2 - Replacing critical raw materials employed in water electrolysis applications as electrocatalysts with earth-abundant materials is paramount for future upscaling to industrial dimensions. In that regard, Ni and Ni-based multimetallic hydroxides, above all NiFe hydroxides, have shown promising performance toward the oxygen evolution reaction (OER) in alkaline conditions. However, it has been shown that the extraordinary performance of these materials is largely due to Fe impurities found in commercial KOH from which electrolyte solutions are prepared. The mechanism of action of these impurities is still not fully understood and, therefore, at the heart of ongoing discussions. In this study, we investigate the OER activity of different nanostructured (Ni1-xFex)OOH samples and find their activities to be influenced differently by the presence of Fe impurities in the electrolyte. From the gathered data, we conclude that the presence of Fe impurities impacts the structure sensitivity of the OER. In purified electrolyte solutions, the OER appears to be a structure-sensitive reaction, while in the presence of Fe impurities, the interaction of the catalyst with these impurities and thus the catalyst surface area becomes paramount.

AB - Replacing critical raw materials employed in water electrolysis applications as electrocatalysts with earth-abundant materials is paramount for future upscaling to industrial dimensions. In that regard, Ni and Ni-based multimetallic hydroxides, above all NiFe hydroxides, have shown promising performance toward the oxygen evolution reaction (OER) in alkaline conditions. However, it has been shown that the extraordinary performance of these materials is largely due to Fe impurities found in commercial KOH from which electrolyte solutions are prepared. The mechanism of action of these impurities is still not fully understood and, therefore, at the heart of ongoing discussions. In this study, we investigate the OER activity of different nanostructured (Ni1-xFex)OOH samples and find their activities to be influenced differently by the presence of Fe impurities in the electrolyte. From the gathered data, we conclude that the presence of Fe impurities impacts the structure sensitivity of the OER. In purified electrolyte solutions, the OER appears to be a structure-sensitive reaction, while in the presence of Fe impurities, the interaction of the catalyst with these impurities and thus the catalyst surface area becomes paramount.

KW - alkaline OER

KW - KOH purification

KW - nanoparticle catalyst

KW - NiFe-LDH

KW - structure sensitivity

U2 - 10.1021/acsanm.3c05983

DO - 10.1021/acsanm.3c05983

M3 - Journal article

AN - SCOPUS:85195028615

VL - 7

SP - 12345−12355

JO - ACS Applied Nano Materials

JF - ACS Applied Nano Materials

SN - 2574-0970

IS - 11

ER -