This thesis presents the commissioning and performance assessment of a lab-scale CO₂-to-formate/fuel cell prototype developed within the FRESH project. The work focuses on two main sections of the prototype: the CO₂ electrolyzer, investigated to identify the operational limitations affecting potassium formate production, and the Direct Formate Fuel Cell, tested to evaluate the conversion of potassium formate into electrical power under laboratory conditions. The CO₂ electrolyzer was tested using different 3-cell stack configurations. A three-chamber gas-fed configuration was compared with a two-chamber configuration in which CO₂ was supplied through the catholyte phase. Polarization curves and constant-current tests were performed to evaluate stack behavior, individual cell responses, and the effects of operating conditions.