TY - JOUR
T1 - Electroconvective Instability in Water Electrolysis
T2 - An Evaluation of Electroconvective Patterns and Their Onset Features
AU - Pande, Nakul
AU - Wood, Jeffery A.
AU - Mul, Guido
AU - Lohse, Detlef
AU - Mei, Bastian T.
AU - Krug, Dominik
N1 - Funding Information:
This research received funding from The Netherlands Organization for Scientific Research (NWO) in the framework of the fund New Chemical Innovations, project ELECTROGAS (731.015.204), with financial support from Akzo Nobel Chemicals, Shell Global Solutions, Magneto Special Anodes (an Evoqua Brand), and Elson Technologies. We acknowledge The Netherlands Center for Multiscale Catalytic Energy Conversion (MCEC) and the Max Planck Center Twente for Complex Fluid Dynamics for financial support. D.L. also acknowledges financial support by an ERC-Advanced Grant.
Publisher Copyright:
© 2021 American Physical Society.
PY - 2021/9/10
Y1 - 2021/9/10
N2 - In electrochemical systems, an understanding of the underlying transport processes is required to aid in their better design. This includes knowledge of possible near-electrode convective mixing that can enhance measured currents. Here, for a binary acidic electrolyte in contact with a platinum electrode, we provide evidence of electroconvective instability during electrocatalytic proton reduction. The current-voltage characteristics indicate that electroconvection, visualized with a fluorescent dye, drives current densities larger than the diffusion transport limit. The onset and transition times of the instability do not follow the expected inverse-square dependence on the current density, but, above a bulk-reaction-limited current density, are delayed by the water dissociation reaction, that is, the formation of H+ and OH- ions. The dominant size of the electroconvective patterns is also measured and found to vary with the diffusion length scale, confirming previous predictions on the size of electroconvective vortices.
AB - In electrochemical systems, an understanding of the underlying transport processes is required to aid in their better design. This includes knowledge of possible near-electrode convective mixing that can enhance measured currents. Here, for a binary acidic electrolyte in contact with a platinum electrode, we provide evidence of electroconvective instability during electrocatalytic proton reduction. The current-voltage characteristics indicate that electroconvection, visualized with a fluorescent dye, drives current densities larger than the diffusion transport limit. The onset and transition times of the instability do not follow the expected inverse-square dependence on the current density, but, above a bulk-reaction-limited current density, are delayed by the water dissociation reaction, that is, the formation of H+ and OH- ions. The dominant size of the electroconvective patterns is also measured and found to vary with the diffusion length scale, confirming previous predictions on the size of electroconvective vortices.
UR - http://www.scopus.com/inward/record.url?scp=85114896137&partnerID=8YFLogxK
U2 - 10.1103/PhysRevApplied.16.034021
DO - 10.1103/PhysRevApplied.16.034021
M3 - Article
AN - SCOPUS:85114896137
SN - 2331-7019
VL - 16
JO - Physical review applied
JF - Physical review applied
IS - 3
M1 - 034021
ER -