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Stable Potential Windows for Long‐Term Electrocatalysis by Manganese Oxides Under Acidic Conditions
Author(s) -
Li Ailong,
Ooka Hideshi,
Bonnet Nadège,
Hayashi Toru,
Sun Yimeng,
Jiang Qike,
Li Can,
Han Hongxian,
Nakamura Ryuhei
Publication year - 2019
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201813361
Subject(s) - electrolysis , oxygen evolution , electrocatalyst , electrolysis of water , electrolyte , catalysis , manganese , oxide , chemistry , metal , inorganic chemistry , chemical engineering , water splitting , materials science , electrode , electrochemistry , organic chemistry , photocatalysis , engineering
Efficient, earth‐abundant, and acid‐stable catalysts for the oxygen evolution reaction (OER) are missing pieces for the production of hydrogen via water electrolysis. Here, we report how the limitations on the stability of 3d‐metal materials can be overcome by the spectroscopic identification of stable potential windows in which the OER can be catalyzed efficiently while simultaneously suppressing deactivation pathways. We demonstrate the benefits of this approach using gamma manganese oxide (γ‐MnO 2 ), which shows no signs of deactivation even after 8000 h of electrolysis at a pH of 2. This stability is vastly superior to existing acid‐stable 3d‐metal OER catalysts, but cannot be realized if there is a deviation as small as 50‐mV from the stable potential window. A stable voltage efficiency of over 70 % in a polymer–electrolyte membrane (PEM) electrolyzer further verifies the availability of this approach and showcases how materials previously perceived to be unstable may have potential application for water electrolysis in an acidic environment.