Unveiling the role of serpentine anode flow field geometry in methanol electrolysis cells through response surface methodology

Abstract

The design of anode flow fields strongly influences the performance of methanol electrolysis cells (MECs) through reactant distribution and product removal within the electrode. Despite its relevance, the quantitative relationship between serpentine flow field geometry and MEC polarization behavior remains insufficiently understood. In this work, this relationship is investigated through a combined experimental and statistical modelling approach. A central composite design (CCD) was employed to systematically vary key geometric parameters of serpentine anode flow fields: channel width, open ratio, and channel depth. Based on this design, fifteen different geometries were fabricated and electrochemically characterized. The resulting polarization curves were fitted to a semi-empirical model, enabling the extraction of local parameters associated with parasitic current losses and effective ohmic resistance. Response surface methodology (RSM) was subsequently applied to correlate these parameters with flow field geometry. The results show that the ohmic contribution to polarization is strongly governed by geometry, with open ratio and channel width identified as the most influential variables. Refined models with coefficients of determination around 0.92 were obtained, providing a predictive framework linking serpentine flow field geometry to MEC performance. This approach offers a practical tool for the optimization of serpentine anode flow field architectures in MEC systems.