Abstract

Developing highly active and stable electrocatalysts for the oxygen evolution reaction (OER) is key to improving the efficiency and practical application of various sustainable energy technologies including water electrolysis, CO2 reduction, and metal air batteries. Here, we use evaporation-induced self-assembly (EISA) to synthesize highly porous fluorite nanocatalysts with a high surface area. In this study, we demonstrate that a 50% rare-earth cation substitution for Ce in the CeO2 fluorite lattice improves the OER activity and stability by introducing oxygen vacancies into the host lattice, which results in a decrease in the adsorption energy of the OH* intermediate in the OER. Among the binary fluorite compositions investigated, Nd2Ce2O7 is shown to display the lowest OER overpotential of 243 mV, achieved at a current density of 10 mA cm-2, and excellent cycling stability in an alkaline medium. Importantly, we demonstrate that rare-earth oxide OER electrocatalysts with high activity and stability can be achieved using the EISA synthesis route without the incorporation of transition and noble metals.

Department(s)

Chemistry

Comments

American Chemical Society Petroleum Research Fund, Grant 62728-DNI3

Keywords and Phrases

electrocatalyst; fluorites; mesoporous; OER; oxygen vacancies, high entropy oxides; rare earth cations

International Standard Serial Number (ISSN)

1944-8252; 1944-8244

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 American Chemical Society, All rights reserved.

Publication Date

14 Feb 2024

PubMed ID

38308595

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