Long-term water electrolysis using a manganese catalyst

March 19, 2019

Potential for hydrogen production independent of rare elements

An international joint research team from RIKEN CSRS and the Chinese Academy of Sciences has successfully developed a manganese catalyst that can electrolyze water continuously for more than 11 months.

Plants (along with other photosynthetic organisms) are the most efficient users of solar energy on earth, creating organic matter such as starch from water and atmospheric carbon dioxide. Many studies have attempted to reproduce this process artificially (artificial photosynthesis), in order to realize a society which is independent from fossil fuels. The key to success lies in harnessing the oxygen evolution reaction (2H2O → 4H+ O2 +4e). Currently, rare metals such as iridium are necessary to perform this reaction efficiently, because non-noble metal catalysts, while abundant, show low activity and quickly decompose or degrade.

In this study, the team synthesized gamma manganese oxide and studied its efficiency for oxygen evolution. By studying the degradation mechanism using visualization techniques, researchers were able to identify the reaction conditions under which the catalyst did not elute. This has allowed water electrolysis to be performed stably for more than 11 months.

These research results are expected to have applications in polymer electrolyte membrane water electrolysis reactors, which shows promise as a clean hydrogen production technology.

Original article
Angewandte Chemie International Edition doi:10.1002/anie.201813361
A. Li, H. Ooka, N. Bonnet, T. Hayashi, Y. Sun, Q. Jiang, C. Li, H. Han, R. Nakamura,
"Stable Potential Windows for Long‐Term Electrocatalysis by Manganese Oxides Under Acidic Conditions".
Ryuhei Nakamura; Team Leader
Ailong Li; International Program Associate
Hideshi Ooka; Postdoctoral Researcher
Biofunctional Catalyst Research Team