Multiphysics Modeling of an Electrolyzer for Ethylene Glycol Electrooxidation to Glycolic Acid: Performance and Transport Analysis

ABSTRACT The ethylene glycol oxidation reaction (EGOR) converts polyethylene terephthalate (PET)‐derived ethylene glycol (EG) into value‐added products such as glycolic acid (GA) and can be paired with the cathodic hydrogen evolution reaction (HER), offering a route to waste‐polyester valorization and lower‐energy hydrogen production. However, membrane electrode assembly (MEA) electrolyzers for EGOR couple fluid flow, species and charge transport, and electrochemical reactions, whereas their polarization curves do not resolve local limitations within the porous anode. Here, we develop a three‐dimensional (3D), steady‐state, single‐channel anion exchange membrane (AEM) electrolyzer model coupling free and porous‐medium flow, concentrated‐species transport, and secondary current distribution. The model resolves EG transport and reaction distributions in a porous nickel foam (NF) anode. At high full‐cell voltages, the model predicts a pronounced through‐plane mass‐transfer limitation. At 1.25 V, the EG concentration near the membrane is approximately 25% of that near the channel and the membrane‐side volumetric current density is approximately 60% lower than its channel‐side value. Increasing anode permeability improves EG penetration into the electrode interior. Concentrated EG solutions can reduce high‐cell‐voltage performance because their greater viscosity restricts reactant transport, whereas greater porosity alleviates mass‐transfer limitations. Within the simulated range, a porosity of 0.90 gives the highest current density, although the gains diminish beyond 0.80. These results identify through‐plane EG transport as a key limitation in the modeled MEA electrolyzer and provide guidance for optimizing porous‐anode structure.