Central to the energy transition is the conversion of water into hydrogen fuel using renewable electricity. Proton exchange membrane (PEM) electrolysis represents a key technology, but scarce precious metal catalysts are currently used for both the hydrogen and oxygen evolution reaction. Although anion exchange membrane (AEM) technology allows the use of abundant materials for both reactions, there is a need to further improve the activity and stability of these catalysts. The COCOON research group at UGent exploits its expertise in atomic layer deposition (ALD) to apply catalysts of a few atomic layers thick uniformly to three-dimensional electrodes. ALD provides precise control over the thickness, composition and morphology of thin layers and nanocatalysts. The goal of this project involves reducing precious metal loading and gaining fundamental insights into the structural properties of catalysts that determine catalytic activity and stability.