Electrolysis Cell for Generating Concentrated Liquid and Gas Product Streams from CO or CO2

Stanford researchers in the Kanan group have developed a electrolysis cell for generating and extracting liquid and gas product streams from CO and CO₂. Previous designs for electrosynthesis of C2+ products from CO or CO₂ suffer from dilute product streams due to low reactant concentration and mixed phase products. Reduction of CO to C2+ products complicates matters by producing mixed phase products: gaseous ethylene or liquid products (acetic acid, ethanol, propanol etc). To overcome this challenge, this cell utilizes interdigitated flow fields, combined with gas diffusion electrodes (GDEs) and a Nafion membrane to simultaneously attain high current density, high selectivity and high single pass conversion (68%) of CO reduction at moderate cell voltages (100 mA cm^-2). Specifically, the Nafion membrane transports concentrated liquid products away from the GDE and is easily isolated from product gas streams (as high as 1.1M sodium acetate). Overall this design improves efficiency of water/ion flux to an electrode to extract concentrated product streams with potential for scaled up synthesis and expansion to CO₂ electrolysis.

Photo description: Cell configuration and schematic of charge flow. Photo credit: Ripatti et al. Joule (2018).

Stage of Research