Armouring Fuel Cells: A New Shell Design Boosts Catalyst Durability

Fuel cells hold immense promise for clean energy, yet their reliance on platinum-cobalt (PtCo) catalysts often leads to rapid degradation. Over time, these catalysts suffer from metal dissolution, the clumping together of nanoparticles—known as agglomeration—and corrosion of their carbon supports. To combat this, researchers have unveiled an integrated strategy that significantly enhances durability without sacrificing performance.

The team engineered a specialised composite carbon support derived from ZIF-8 and polyaniline. This structure features a high-surface-area core encased within a protective graphitic shell. This outer layer acts as a sturdy barrier, safeguarding the delicate internal structure against the harsh acidic and oxidative environment found inside a fuel cell.

Crucially, the scientists synthesised an ordered Pt3Co 'intermetallic' structure—a specific type of alloy with a strictly defined crystal arrangement—using a gaseous cobalt deposition process. This technique coats platinum nanoparticles with a uniform cobalt-rich layer, which facilitates diffusion into the platinum crystal during heating. The process also generates a thin carbon layer on the nanoparticles, preventing them from growing too large and stopping cobalt from dissolving. The result is a highly resilient catalyst that maintained impressive current density after 120,000 cycles under heavy-duty conditions, marking a vital step forward for sustainable energy technology.