Boosting Fuel Cells: A New Twist on Catalysts

Fuel cells are like the heart of clean energy. They convert hydrogen into electricity. But there's a catch. The process isn't as smooth as it could be. Especially in alkaline environments. The hydrogen oxidation reaction (HOR) is often slow and easily disrupted by carbon monoxide (CO). This is a big problem for anion exchange membrane fuel cells (AEMFCs). Scientists have been experimenting with different materials to speed up this reaction. One promising candidate is cobalt (Co) with a hexagonal close-packed (hcp) structure. But how can we make the most of this material? That's where things get interesting. Researchers have found a way to combine cobalt with ruthenium (Ru) to create nanocrystals. These nanocrystals are anchored on carbon nanosheets. The result? A catalyst that performs better than others in alkaline conditions. This new catalyst, hcp CoRu/C, shows a mass activity of 886 A g Ru -1 at 50 mV. That's a significant improvement over other catalysts like fcc CoRu/C, Pt/C, and Ru/C. But what makes this catalyst so special? It's not just about the materials used. The structure matters too. The hcp phase of CoRu stabilizes the Ru sites. This stabilization weakens the binding energy of hydrogen and optimizes the adsorption energy of hydroxyl. In simpler terms, it makes the reaction faster and more efficient. Plus, it's more resistant to CO poisoning. This breakthrough shows that tweaking the crystal structure of catalysts can be a game-changer. It offers a new way to improve fuel cell technology. Instead of just changing the composition, we can engineer the crystallographic phase. This could lead to more robust and efficient catalysts for alkaline fuel cells.