Electrocatalytic reaction-driven flow

Immobilized electrocatalytic surfaces are capable of generating reaction-driven fluid flow by electrochemical energy conversion. A well-known system concerns the gold-platinum bimetallic motor driven by hydrogen peroxide conversion. In this work, we focus on experimental and numerical analyses that provide fundamental insight on the key elements that control the resulting transport characteristics in this system, including the generated electric field, reaction kinetics, and diffusio-electro-osmotic phenomena. The current between the electrodes and the induced potential that governs the reactive fluxes are measured electrochemically, while the fluid flow is analyzed using particle tracking velocimetry. Numerical simulations based on the Poisson-Nernst-Planck and Navier-Stokes equations reveal the interplay of the individual electrode surface reactivity, represented by the dimensionless Damköhler numbers, with the electrokinetic phenomena.