The high cost of platinum is one of the main barriers to the wider adoption of hydrogen fuel cells. Now, researchers at IMDEA Materials Institute have developed a catalyst that delivers the same performance while using 75% less of this expensive metal.

The study, published in Electrochimica Acta, demonstrates a breakthrough made possible by applying controlled mechanical compression to the catalyst. This modifies its atomic-scale structure, enabling it to achieve energy efficiency comparable to that of pure platinum.

Since platinum is the most expensive component of these catalysts, reducing its use by 75% would significantly lower the manufacturing cost of these clean energy devices.

“This breakthrough demonstrates that elastic strain engineering is a viable and precise strategy for designing much more cost-effective catalysts,” explains IMDEA Materials’ Jorge Redondo, the study’s lead author.

“By reducing the platinum content by three-quarters while maintaining comparable catalytic performance, this work represents a promising step towards the large-scale production of more competitive hydrogen technologies.”

Hydrogen fuel cells, which generate electricity from hydrogen and oxygen, are expected to play a key role in the energy transition.

However, the oxygen reduction reaction (ORR), which produces water as a by-product, is one of the slowest steps in the process.

To accelerate this reaction, fuel cells typically rely on platinum-based catalysts because platinum combines high catalytic activity with excellent operational stability.

To reduce this dependence, the researchers developed a catalyst based on a copper-platinum (Cu₃Pt) alloy deposited onto a nickel-titanium shape-memory substrate. By applying a slight mechanical compression of less than 1%, they altered the catalyst’s electronic structure, significantly enhancing its ability to catalyse the reaction.

Specifically, electrochemical tests showed that the compressed catalyst reached a potential of 855 millivolts at a current density of 1 mA/cm², virtually identical to the 856 millivolts achieved by pure platinum under the same conditions in an acidic environment with a pH close to 1.

By contrast, applying tensile strain by stretching the alloy by 0.80% led to a significant decline in performance. This behaviour experimentally validates theoretical predictions based on changes in the hydrogen adsorption/desorption strength on the catalyst surface.

The analyses also confirmed that the electrochemical process itself induces selective dissolution of copper from the catalyst surface.

“This creates a thin platinum-enriched layer just a few nanometres thick over the underlying structure,” says Redondo. “The combined effect of mechanical compression and chemical self-organisation makes it possible to dramatically reduce the amount of platinum required without sacrificing efficiency.”

Despite these promising results, the authors emphasise that further work is needed before the technology can be commercialised.

The catalyst must demonstrate that it can be manufactured cost-effectively at industrial scale and that the compression-induced effect, which is essential for maintaining its high performance, remains stable during long-term operation. These will be the focus of the next stage of the research.

In addition to Redondo, the study involved Dr. Miguel Monclús, Prof. Jon Molina and Prof. Javier LLorca.

This work was supported by the CATbyESE project (TED2021-129497B-I00), funded by the Spanish Ministry of Science and Innovation. JR acknowledges support from the Spanish Ministry of Science and Innovation through the PRE2021-097425 fellowship. TEM characterisation was carried out at the Transmission Electron Microscopy Unit of Carlos III University of Madrid.