LAUSR

Electrochemical energy conversions require highly active and stable electrocatalysts. The development of such catalysts often occurs in academia, but the transition to industrial applications remains challenging. To study the activity and stability of electrocatalysts under more industrially relevant conditions, we designed an electrochemical flow cell (EFC) with 1 cm2 parallel electrodes compatible with downstream analysis. Precise activity determination over a wide potential range and minimal dilution of reaction products with a restricted volume flow are ensured by a small reaction volume over the working electrode and by minimizing the inhomogeneities of mass transport of reactive species. Thereby, the influence of the reactive species' mass transport on the precision of the activity determination can be neglected. To evaluate this, we modeled the flow velocity distribution, concentration distribution, and particle flux of the reactive species over the electrode surface for different designs with COMSOL Multiphysics. The activity determination via the Koutecký-Levich analysis for the final EFC was simulated and experimentally validated. By coupling the EFC to online electrolyte analysis, the Fe concentration was successfully monitored during cyclic voltammetry and constant current operation at 10 mA cm-2 with a Ni70Fe30 anode in 1 M KOH at room temperature.