Polymorph γ-MnO<sub>2</sub> with Optimal Phase Composition for Stable Oxygen Evolution Reaction in Acid
The development of non-noble-metal oxygen evolution reaction (OER) electrocatalysts stable in acid to replace rare and expensive iridium catalysts is crucial yet challenging for the large-scale application of proton exchange membrane (PEM) water electrolysis technology. Here, we show that increasing the Pr (pyrolusite ratio) in γ-MnO2 from 73% to 84% results in about 10 times longer durability at a high working current density of 100 mA cm–2 in 1 M H2SO4 for more than 1000 h. Dramatic stability enhancement is due to the inhibition of lattice Mn or O dissolution by leveraging the formation of more stable corner-shared pyrolusite MnO6 octahedra with a higher oxidation state of Mn, fewer defects, a shorter Mn–O bond distance, an increase in stable mono-oxo-bridged Mn–O–Mn pyrolusite MnO6 octahedra, and a decrease in di-oxo-bridged Mn–O2–Mn ramsdellite MnO6 octahedra with more Mn–Mn tension. Because polymorph materials like γ-MnO2 are quite common in nature, phase composition turning may serve as an effective strategy for the development of stable OER catalysts in acidic environments.
Authors
- Ailong Li (ORCID: https://orcid.org/0000-0003-0875-5072)
- Daisuke Hashizume (ORCID: https://orcid.org/0000-0001-7152-4408)
- Taifeng Liu (ORCID: https://orcid.org/0000-0002-6869-7022)
- Ryuhei Nakamura (ORCID: https://orcid.org/0000-0003-0743-8534)
- Shuang Kong (ORCID: https://orcid.org/0000-0003-1651-6581)
- Hongxian Han (ORCID: https://orcid.org/0000-0002-2522-1817)
- Lin Liu (ORCID: https://orcid.org/0000-0002-0310-5946)
- Kiyohiro Adachi (ORCID: https://orcid.org/0000-0002-8224-8602)
- Qinqin Hu
- Can Li (ORCID: https://orcid.org/0000-0002-9301-7850)
- Pengfei Zhang (ORCID: https://orcid.org/0000-0003-2674-3825)
- Yimeng Sun (ORCID: https://orcid.org/0000-0003-3557-6133)
Institutions
- Tokyo Institute of Technology (JP)
- Henan University (CN)
- Dalian Institute of Chemical Physics (CN)
- Chinese Academy of Sciences (CN)
- RIKEN Center for Sustainable Resource Science (JP)
- Life Science Institute (JP)
- RIKEN Center for Emergent Matter Science (JP)
- Dalian National Laboratory for Clean Energy (CN)
- University of Chinese Academy of Sciences (CN)
Publication Details
- Journal
- ACS Sustainable Chemistry & Engineering
- Published
- 2024-11-25
- DOI
- https://doi.org/10.1021/acssuschemeng.4c06977
- Citations
- 5
- Primary Topic
- Electrocatalysts for Energy Conversion
- Type
- article
- Field-Weighted Citation Impact
- 0.51
Funders
- National Natural Science Foundation of China
- National Key Research and Development Program of China