Decreasing the Energy Consumption of the CO₂ Electrolysis Process Using a Magnetic Field

The renewable electricity-powered electrolysis of CO2 could be a viable carbon-neutral method for producing carbon-based value-added chemicals like carbon monoxide, formic acid, ethylene, and ethanol. A typical CO2 electrolyzer suffers, however, from the high power requirements, mainly due to the energy-intense anode reaction. In this work, we decrease the anode overpotential and thus reduce the overall cell energy consumption by using a NiFe-based bimetallic catalyst at the anode and applying a magnetic field. For a CO2 electrolysis process producing CO in a gas diffusion electrode-based flow electrolyzer, we demonstrate that power savings in the range from 7% to 64% can be achieved at CO partial current densities exceeding −300 mA/cm2 using a NiFe catalyst at the anode and/or by using a magnetic field at the anode. We achieve a maximum CO partial current density of −565 mA/cm2 at a full cell energy efficiency of 45% with 2 M KOH as the electrolyte.