A photo-electro-catalytic (PEC) cell for direct conversion of water and carbon dioxide into chemicals (CO2 reduction) and oxygen (water oxidation) using exclusively solar energy will be designed, built, validated and optimized. The cell will be constructed from cheap photo-electrodes able to transform sun irradiation into an electrochemical potential difference; ultrathin nanostructured layers of catalysts for both half reactions; and membrane technology for gas/liquid/products separation to maximize performance. Achieving this goal, we will improve the state-of-the-art of all components for the sake of cell integration:

1. Surface sciences: metal and metal oxide catalysts will be characterized through spatially resolved experiments (scanning probe microscopy) in operando electrochemical reactions. Activity and performance will be correlated to composition, nanostructure and solid support;
2. Photoelectrodes: Multiple termodynamic and kinetic techniques will allow characterization and optimization of electrodecatalysts interfaces to identify best matching between light absorbers and chemical catalysts along optimum working conditions (pH, electrolyte, temperature, pressure)
3. Modeling: Materials, catalysts and processes will be modeled with computational methods as a pivotal tool to understand photo-catalytic-electrodes performance to bring them to their theoretical limits; the selected optimum materials and environmental conditions as defined from these parallel studies will be integrated into a PEC cell prototype. This design will include ion exchange membranes and gas diffusion electrodes for product separation. Performance will be validated in real working conditions under sun irradiation to assess the technological and industrial relevance of this A-LEAF cell.