Electrolysis Cell for Concentrated Chemical Product Streams from CO or CO2

Stanford researchers in the Kanan group have developed a patented electrolysis cell for generating and extracting concentrated liquid and gas product streams from CO and CO₂. Prior C₂₊ products electrosynthesis designs suffer from dilute product streams due to low single-pass conversion, compounded by the challenge of managing mixed-phase products (gaseous ethylene alongside liquid products like acetic acid, ethanol, propanol, etc.). To overcome this, the cell combines interdigitated flow fields, gas diffusion electrodes (GDEs), and a Nafion membrane to simultaneously achieve high current density (100 mA cm?²), high selectivity, and high single-pass CO conversion (68%) at moderate cell voltages. The Nafion membrane transports concentrated liquid products (up to 1.1 M sodium acetate) away from the GDE while remaining easily isolated from the gas product stream. This design improves water/ion flux efficiency at the electrode to extract concentrated product streams, with potential for scale-up and extension to CO₂ electrolysis.

Stage of Development - Prototype
The Kanan group demonstrated >100 mA/cm² CO reduction to C₂₊ products and direct production of 1.1 M acetate at a cell potential of 2.4 V over 24 hours using a cell with the GDE directly contacting a Nafion membrane.