PEM water electrolysis using a non-noble metal catalyst

January 17, 2024

Discovery of a strategy for enhancing the stability of manganese oxide catalyst

An international joint research group of RIKEN CSRS, RIKEN CEMS, and Dalian Institute of Chemical Physics (CAS) and Westlake University in China have discovered a rational strategy to enhance the stability of manganese oxide (MnO2) as a promising catalyst for water electrolysis.

The research team had found out in 2019 that manganese oxide catalysts are capable of electrolyzing water stably under an acidic environment. While manganese oxide showed excellent stability at low current density in the conventional three-electrode system, it suffered from severe dissolution at high current density in the proton exchange membrane (PEM) environment. Therefore, there is a pressing need to further enhance the stability of manganese oxide.

In the current study, the international joint research group succeeded in enhancing the stability of manganese oxide catalyst under acidic environments by optimizing its lattice structure at the atomic level. The optimized manganese oxide catalyst can sustainably produce hydrogen for over 1,000 hours at a current density of 200 mA/cm2, not only in the three-electrode system used in fundamental studies, but also in the more realistic PEM environment. This stability corresponds to an order-of-magnitude increase in the total hydrogen produced compared with previously reported non-noble catalysts.

The achievement of this study is expected to be applicable to PEM water electrolysis, which has attracted significant attention as a promising technology for green hydrogen production.

Original article
Nature Catalysis doi: 10.1038/s41929-023-01091-3
S. Kong, A. Li, J. Long, K. Adachi, D. Hashizume, Q. Jiang, K. Fushimi, H. Ooka, J. Xiao, R. Nakamura,
"Acid-stable manganese oxides for proton exchange membrane water electrolysis".
Shuang Kong; Research Scientist
Ailong Li; Research Scientist
Ryuhei Nakamura; Team Leader
Biofunctional Catalyst Research Team