Mass transfer enhancement in electrochemical flow cells through 3D-printed biomimetic channels

Abstract

Mass transfer is frequently the rate-limiting step in electrochemical processes. In addition to increasing electrolyte flow rate, transfer limitations in electrochemical flow cells can be mitigated by inducing turbulence in the flow fields. This can be achieved by substituting the conventional rectangular channel cell design for flow fields that promote chaotic movement in the electrolyte. In this work, a novel biomimetic channel concept based on space-filling curves created by differential growth, such as those present in rippled surfaces of plants and river meanders, is proposed. The overall performance was analyzed in an undivided flow cell by the limiting current technique as a function of electrolyte flow rate. The performance of the biomimetic flow field is enhanced on average by a factor of 1.9 and 1.1 with respect to the rectangular and serpentine flow fields, respectively. The designed flow field increased pressure drop in comparison to the other flow fields but at levels similar to the typical FM01-LC flow reactor with porous electrodes. Differential growth flow fields open a window to further application in inorganic and organic flow electrosynthesis at various scales, as this parametric design allows for channel adaption to the reaction requirements.