Overcoming mass transport limitations is a central challenge that constrains the efficiency of diverse electrochemical technologies, from industrial electrosynthesis to energy storage. Here, we establish a design framework for the quantitative, predictive control of solution-phase fluid dynamics using Lorentz forces, transforming this phenomenon from a physical curiosity into a robust chemical engineering tool. Using the electrochemical oxidation of iodide as a tracer-free model system, we directly visualize and deconstruct the parameters governing magneto-hydrodynamic convection. We provide quantitative correlations linking key chemical (reactant concentration, electrolyte viscosity) and physical (applied potential, magnetic field strength) parameters to the resulting fluidic motion.1 This analysis reveals a fundamental insight: both the electric and magnetic components of the Lorentz force create observable, controllable transport effects extending millimeters from the electrode surface. This work provides a non-mechanical strategy to rationally engineer fluid dynamics in electrochemical reactors, opening a clear pathway to predictably enhance rates in diffusion-limited electrocatalysis and homogenize interfacial processes in batteries.
1 Jiang, H. J.; Abd El-Rahman, M-K.; Brazaca, L. C.; Underwood, T. C.; Sakamoto, J.; Bell, J. G.; Whitesides, G. M.*; “Methods and Systems for Generating Liquid Motion” (PCT/US23/74287)