Gastight rotating cylinder electrode: Toward decoupling mass transport and intrinsic kinetics in electrocatalysis

Abstract

Decoupling and understanding the various mass, charge, and heat transport phenomena involved in the electrocatalytic transformation of small molecules (i.e., CO 2 , CO, H 2 , N 2 , NH 3 , O 2 , and CH 4 ) is challenging but it can be readily achieved using dimensionless quantities (i.e., Reynolds, Sherwood, Schmidt, Damköhler, Nusselt, Prandtl, and Peclet Numbers) to simplify the characterization of systems with multiple interacting physical phenomena.Herein we report the development of a gastight rotating cylinder electrode cell with welldefined mass transport characteristics that can be applied to experimentally decouple mass transfer effects from intrinsic kinetics in electrocatalytic systems. The gastight rotating cylinder electrode cell enables the dimensionless analysis of electrocatalytic systems and should enable the rigorous research and development of electrocatalytic technologies.

2022 roadmap on low temperature electrochemical CO2 reduction

“…While ohmic overpotentials are typically compensated through IR correction, concentration overpotentials are germane to CO 2 R as CO 2 has relatively low solubility in aqueous electrolytes and measurements are typically conducted in neutral pH without strong buffering agents. Rotating disk electrode (RDE) measurements (figure 5(A)), that hydrodynamically control external diffusion within the boundary layer, are uncommon in CO 2 R as it is challenging to form a gas-tight seal for product analysis [45,46]. Thus, conventional analytical methods to deconvolute mass transport effects, such as Koutecky-Levich analysis at various rotational rates (ω) (figure 5(B)), are typically not used for CO 2 R, and researchers are left with difficult decisions hypothesizing which data represents the intrinsic reaction kinetics.…”

“…Further development and more widespread adoption of gas-tight RDE and liquid flow cells for benchmarking will deconvolute intrinsic reaction rates from mass transport effects [45,46]. Reporting uncertainties in data, and importantly, propagating the error through all analyses is strongly encouraged.…”

Designing Cu-Based Tandem Catalysts for CO2 Electroreduction Based on Mass Transport of CO Intermediate

“…Another opinion is that the residence time of the CO intermediate in the proximity of the Cu surface rather than the local concentration of CO determines the rate of the further reduction of CO to highly reduced products. Jang et al conducted CO 2 reduction on polycrystalline Cu in a gas-tight rotating cylinder electrode cell . In such a cell, the mass transport of CO 2 and CO intermediate can be controlled quantitatively.…”

“…r 4 represents the rate of CO flux out of the electrode. Reproduced with permission from ref . Copyright 2022 Wiley-VCH.…”

“…Surface-enhanced Raman spectroscopy (SERS) and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) are powerful tools to probe the local concentration of CO, coverage of *CO, and local pH. , Cu deposited on Au with a regular pattern was a good model catalyst, on which the diffusion of CO in the solution phase can be simulated mathematically. It is noteworthy that even when strong convection is introduced over a flat electrode of CO-formation catalyst, the CO produced from the electrode cannot be transported away from the electrode at the same rate at which CO is produced . CO molecules accumulated within the viscous sublayer always have a contribution to the formation of highly reduced products.…”