Electrolyzers for the Reduction of Carbon Dioxide to Formate

An aspect of the present disclosure is an electrochemical flow cell that includes a gap positioned between an ion exchange membrane (IEM) and a cathode gas diffusion electrode (GDE), where the gap is positioned to contain a liquid, the gap has a thickness value, as defined by the distance between the IEM and the cathode GDE, of between greater than zero mm and less than about 2.0 mm. In some embodiments of the present disclosure, the gap may be between about 0.1 mm and about 1.0 mm. In some embodiments of the present disclosure, the gap filled with the liquid may provide a conductivity of greater than about 5 S/m. In some embodiments of the present disclosure, the electrochemical flow cell may further include a cathode flow plate, where the cathode GDE is positioned between the IEM and the cathode flow plate, and the cathode flow plate includes a serpentine flow path. In some embodiments of the present disclosure, the electrochemical flow cell may further include at least two contacts configured to estimate a voltage drop across the electrochemical cell.