The goal of this interdisciplinary project is the electro-driven synthesis of fine chemicals using biocatalysts. However, many biocatalysts require cofactors for functionality. However, stoichiometric addition of reduced cofactors, such as NADH, is too expensive. Molecular hydrogen (H2) as the fuel of the future represents a cheap, efficient and environmentally friendly reducing agent. The central enzyme of our system is a hydrogenase that uses H2 as a reducing agent and can reduce cofactors with it. Our new approach is based on in situ H2 synthesis by electrolysis. Here, the electrolysis module is separated from the biological catalysts by a H2-permeable Teflon tube to avoid harsh conditions for biological catalysts. The goal is to demonstrate the broad applicability through validation and "up-scaling" in order to eventually market our technology successfully as a product.