New water splitting catalysts make green hydrogen without expensive metals

Highlights

• ANEMEL addressed two important challenges in green hydrogen production: avoiding platinum group metals and achieving high stability in anion exchange electrolysers.
• These electrolysers operated at an ultra-high current density of 10 A/cm² for 800 hours – which represents a 500,000-fold increase in performance compared to state-of-the-art benchmarks.
• The new platinum-free catalyst for the generation of green hydrogen showed a stable behaviour at current densities as high as 3 A/cm².

Press release

ANEMEL, a European project funded by the European Innovation Council, has presented two ground-breaking scientific studies in water splitting, demonstrating highly stable anion exchange membrane electrolysers without using expensive and scarce platinum-group catalysts. These electrolysers surpass state-of-the-art solutions in both performance and long-term stability, which could create viable industrial applications sooner than expected.

Green hydrogen production holds promise within the energy transition landscape, especially for its potential as a clean fuel that burns without generating greenhouse gas emissions. A common route towards green hydrogen is water splitting – the separation of water into its components, hydrogen and oxygen, using renewable energy sources and devices called electrolysers.

In this field, anion exchange membrane water electrolysers (AEMWEs) have gained considerable attention from researchers and industry, due to their capability to produce hydrogen under more environmentally friendly conditions. Now, ANEMEL researchers have broken records in AEMWE technology, achieving great stability without employing expensive and scarce metals, such as platinum. 

The first study, recently published in Angewandte Chemie, demonstrated AEMWEs operating at an ultrahigh current density of 10 A/cm² for over 800 hours, without a decrease in performance. In comparison, state-of-the-art benchmark electrolysers only sustain such current densities for a few seconds. This represents an impressive 500,000-fold increase in performance.

“The results are really good, operating at 10 A/cm² for that amount of time is quite amazing, I honestly had never seen it before,” says ANEMEL researcher and co-author Ariana Serban, who works at Xile Hu’s group at ANEMEL partner the École Polytechnique Fédérale de Lausanne (EPFL), in Switzerland.

The second study, published by the same group in the journal Energy & Environmental Science, focused on the development of a platinum-free cathode catalyst for the hydrogen evolution reaction (HER). ANEMEL researchers observed record-breaking performances, which allowed electrolysers to operate stably at current densities as high as 3 A/cm². Such results are slightly superior to state-of-the-art benchmarks with more expensive and scarce platinum catalysts. According to Serban, “this achievement ranks among the top 100, or even top 50, in terms of performance for non-platinum catalysts.”

Increasing current density could achieve a higher hydrogen production rate, thereby reducing the overall electrolyser’s footprint, volume, and material usage. This could improve efficiency and lower the cost of hydrogen production. Additionally, the increased stress during high current operations could serve as a rapid assessment tool for device robustness, eliminating the need for lengthy tests spanning thousands of hours. Moreover, the avoidance of platinum-group metals and opting instead for abundant materials, such as nickel and iron, decreases the cost of components and improves recyclability, reducing waste and providing a competitive advantage. 

While challenges remain, these two studies mark significant progress toward the goal of affordable, sustainable hydrogen production on an industrial scale. The ANEMEL team will continue working to refine electrolyser designs and catalyst development to further advance in this direction.

About ANEMEL

Green hydrogen is a key ingredient towards the decarbonisation of the European economy. ANEMEL, a project funded by the European Innovation Council and led by the National University of Galway (Ireland), is exploring new methods to produce green hydrogen from low-quality water sources, such as seawater and wastewater. ANEMEL will develop efficient electrolysers and expedite the design of prototypes, aiming to catalyse the commercialisation and exploitation of the technology. 

The project aligns within a broader European Commission initiative to design and test novel routes for producing green hydrogen. Obtained by splitting water into its basic elements—hydrogen and oxygen—using renewable energy sources, green hydrogen could replace fossil fuels in transportation and industry. Moreover, it provides a cleaner raw material for the chemical industry, enabling the production of sustainable fertilisers, feedstocks, and fundamental materials like steel.

ANEMEL gathers expertise in the field of membranes and electrolysers – the overall goal is a prototype that yields green hydrogen from low-grade water with minimal treatments. Additionally, the oxygen obtained could find uses in the treatment and purification of the water sources. The membranes designed by ANEMEL will avoid using persistent and pollutant products like poly-fluorinated materials, as well as critical raw materials, favouring the use of abundant metals like nickel and iron. All this will reduce the cost of the electrolyser components and improve their recyclability, thus reducing waste and providing a competitive advantage.