Japanese researchers have made a significant breakthrough in green hydrogen production, developing a low-cost manganese-based catalyst capable of producing up to 1,000% more hydrogen through electrolysis — a discovery that could drastically reduce reliance on expensive rare metals such as iridium and platinum.
The research, conducted by scientists at Japan’s RIKEN Institute and published in Nature Catalysis, focuses on proton exchange membrane (PEM) electrolysers, a technology widely regarded for its efficiency and responsiveness in converting water into hydrogen using renewable electricity.
Until now, these systems have heavily depended on costly and scarce noble metals to facilitate the chemical reactions required.
The core of the innovation lies in a modified form of manganese oxide (MnO₂), a common and abundant metal.
By engineering its three-dimensional lattice structure, researchers succeeded in significantly strengthening the material’s bond with oxygen atoms — a key step in improving its catalytic performance.
In laboratory trials, the restructured manganese oxide demonstrated remarkable durability and efficiency, operating continuously for over 1,000 hours at a current density of 200 mA/cm².
The result: a tenfold increase in hydrogen output compared with previous non-noble metal catalysts.
According to the study, the new MnO₂ catalyst is not only more stable in acidic environments, a crucial requirement for PEM electrolysers, but also extends the lifespan of other low-cost catalysts by a factor of 40.
This makes it one of the most promising non-precious alternatives for sustainable hydrogen production.
Green hydrogen, produced via water electrolysis powered by renewable sources, is considered a vital component in the transition to clean energy.
Countries such as Spain have already placed significant investment into green hydrogen as a long-term solution to decarbonising heavy industry and transport.
However, the use of rare metals in electrolysis has presented a major economic and environmental hurdle. Iridium, often used to catalyse oxygen conversion in PEM systems, is one of the rarest elements on Earth.
Replacing it with a stable, low-cost alternative could help scale hydrogen production globally without the supply chain risks tied to rare metals.
While the manganese-based catalyst marks a major scientific advance, researchers caution that further development is necessary before the material is deployed at industrial scale.
Efforts are ongoing to improve the current density and operational lifespan of the catalyst under real-world conditions.
The discovery holds several far-reaching implications for the global energy landscape.
By eliminating the need for expensive noble metals such as iridium and platinum, the manganese-based catalyst could significantly lower the cost of producing green hydrogen. This would enhance the economic viability of hydrogen as a clean energy carrier and make it more accessible for widespread industrial use.
Furthermore, manganese is abundant and widely available, in contrast to the scarce and geopolitically sensitive supply chains associated with iridium.
Substituting manganese for rare metals may alleviate supply bottlenecks and reduce dependence on limited global sources, supporting more secure and scalable hydrogen infrastructure deployment.
The enhanced durability of the catalyst — which maintained continuous operation for over 1,000 hours in laboratory testing — also suggests improved lifespan and efficiency for PEM electrolysers.
This could reduce maintenance requirements and operational downtime, resulting in better long-term performance and lower total system costs.
If successfully translated to industrial applications, the technology may accelerate the decarbonisation of sectors that are difficult to electrify, such as steelmaking, chemical production and long-haul transport.
It also supports broader integration of green hydrogen into energy systems as a storage medium for surplus renewable power.
While further validation is necessary under real-world operating conditions, the innovation marks a promising step toward more sustainable and commercially viable hydrogen production — and may ultimately help drive the global transition to a low-carbon energy future.
Still, the RIKEN team believes this innovation could be a decisive step toward making iridium-free water electrolysis a commercial reality — a prospect that could reshape the economics of the global hydrogen sector.
