Electrochemical CO₂ fixation has become one of the major research fields in the area of electrocatalysis and energy conversion. Despite several improvements with respect to catalyst activity and minimization of overpotentials, the selectivity of these inorganic catalysts is rather low and usually mixtures of various products are produced that have to be separated in time and energy consuming complex steps. Nature provides highly active and selective bio(electro)catalysts, i.e. (redox) enzymes, that were developed and optimized over billions of years. The main goal of this project is to exploit the capability of this enzymatic conversion to in a novel light-powered system based on a combination of biocatalyst that are wired to the electrodes by redox polymers by simultaneous application of gas diffusion and high surface area electrodes to enhance mass transport and catalyst loading. Additionally, the use of enzyme cascades to ensure high selectivity and targeted product formation as well as the use of H₂O as electron source, makes this system unique and will be a breakthrough in the design of new solar-to-chemicals devices.