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Hydrogen fuel cells are widely seen as a cornerstone of a low-carbon energy future – powering everything from vehicles to backup energy systems. But their wider adoption still faces a major obstacle: the reliance on precious metal catalysts, which are scarce, expensive and vulnerable to supply constraints.

published in RSC Applied Interfaces suggests a promising way forward. Instead of focusing solely on catalyst chemistry, researchers have explored how engineering the architecture of the catalyst support could unlock the performance of platinum-group-metal-free (PGM-free) cathodes.

Rethinking the catalyst layer

Most research aimed at improving fuel cells focuses on improving the activity of catalytic materials by optimising the active site environments. In this study, the team took a different approach: redesigning the physical structure of the cathode itself to improve mass transport of conventional catalyst materials

The researchers developed a freestanding macroporous carbon film designed to support iron–nitrogen–carbon (Fe–N–C) catalysts, one of the most promising alternatives to platinum for the oxygen reduction reaction.

Unlike conventional carbon supports, the film contains an interconnected network of large pores. This architecture allows oxygen and reaction products to move more freely through the catalyst layer – a crucial factor for maintaining performance when fuel cells operate at high current densities.

By focusing on the structure surrounding the catalyst rather than the catalyst alone, the approach addresses one of the key limitations that has slowed the adoption of PGM-free materials.

Performance where it matters

When tested in a gas-diffusion electrode system under conditions relevant to real fuel cell operation, the macroporous carbon film enabled stronger cathode performance than conventional carbon supports.

For platinum-free catalysts – which often require thicker catalyst layers than platinum-based systems – restricted mass transport can quickly limit efficiency. Opening up the electrode structure helps overcome this bottleneck and allows the catalyst to operate more effectively.

Supporting the hydrogen economy

Reducing or eliminating precious metals from fuel cell catalysts could significantly lower system costs while reducing reliance on critical metals.

Catalysts based on iron, nitrogen and carbon are far more abundant, making them an attractive route toward scalable fuel cell technologies. Advances like this could help accelerate the development of more affordable hydrogen solutions – from cleaner vehicles to decentralised power generation and energy storage.

to discover how structural design could help bring platinum-free fuel cells closer to real-world applications.

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