Modeling and Experimental Validation of Electrochemical Reduction of CO₂to CO in a Microfluidic Cell

A steady-state isothermal model is presented for the electrochemical reduction of CO2 to CO in a microfluidic flow cell. The full cell model integrates the transport of charge, mass, and momentum with electrochemistry for both the cathode and anode. Polarization curves obtained from experiments conducted at different flow rates with varying applied cell potentials are used to determine the kinetic parameters in the electrochemical reaction rate equations. The parameterized model is validated using a different set of experimental results. Good agreement is observed, especially at high cell potentials (–2.5 to –3 V). The model is further used to analyze the effects of several operating parameters, such as applied cell potential, CO2 concentration of the feed and feed flow rates. The use of the model to analyze the effect of design parameters, such as channel length and porosity of the gas diffusion electrodes, is also demonstrated.