Département de chimie moléculaire

The future of energy supply depends on innovative breakthroughs regarding the design of cheap, sustainable and efficient systems for the conversion and storage of renewable energy sources. The production of H through H2O splitting seems a promising and appealing solution A robust nanoparticulate electrocatalytic material, H2-CoCat, can be electrochem. prepared from Co salts in a phosphate buffer. This material consists of metallic Co coated with a Co-oxo/hydroxo-phosphate layer in contact with the electrolyte and mediates H2 evolution from neutral aqueous buffer at modest overpotentials. Remarkably, it can be converted on anodic equilibration into the previously described amorphous Co oxide film (O2-CoCat or CoPi) catalyzing O2 evolution. The switch between the two catalytic forms is fully reversible and corresponds to a local interconversion between two morphologies and compositions at the surface of the electrode. After deposition, the noble-metal-free coating thus functions as a robust, bifunctional and switchable catalyst.