Modeling Oxygen Gas Diffusion Electrodes for Various Technical Applications

Abstract

In gas diffusion electrodes (GDEs), electrocatalysts are in contact with gas and electrolyte ensuring a large active threephase boundary. GDEs are used for important technical applications in energy transformation and chemical synthesis. This review gives an introduction into the vast range of existing models for GDEs and their specific purpose, with an emphasis on oxygen reduction electrodes. After introducing the processes occurring in GDEs, modeling approaches are described according to their dimensionality (from 0D to 3D to multiscale) and perspectives for future research are discussed.

Influence of Temperature on the Performance of Gas Diffusion Electrodes in the CO2 Reduction Reaction

“…To determine the limiting current density of CO 2 RR, indicated by the deviation from the exponential increase in Figure a, the “thin film model” must be used, because film diffusion limitation of CO 2 is the maximum limitation possible . All situations in between are described by the “thin film flooded agglomerate model” . Corresponding to the flooded agglomerate model it is assumed that CO 2 mass transport into flooded agglomerates of carbon nanoparticles takes place in order to reach the SnO x active sites supported on carbon (see the Supporting Information).…”

“…[72,73] All situations in between are described by the "thin film flooded agglomerate model". [74,75] Corresponding to the flooded agglomerate model it is assumed that CO 2 mass transport into flooded agglomerates of carbon nanoparticles takes place in order to reach the SnO x active sites supported on carbon (see the Supporting Information). Based on 1 st Fickian and 1 st Faraday's law an equation for the current density at which HER starts to increase can be derived assuming that CO 2 concentration reaches zero in the center of the agglomerate [Eq.…”

Analysis of Electrochemical Impedance Spectroscopy on Zinc-Air Batteries Using the Distribution of Relaxation Times

“…In order to prevent such processes, it is necessary to gain a fundamental understanding of the reactions and their interactions [20]. One common method for this is the electrochemical impedance spectroscopy (EIS) [21], which is used for material optimization and modeling besides process analysis and quantification [22][23][24][25][26][27][28][29]. In addition to the visual evaluation of the impedance data, fitted equivalent circuit models (ECM) are used for quantification [21].…”

The Key Role of Water Activity for the Operating Behavior and Dynamics of Oxygen Depolarized Cathodes

“…The oxygen reduction reaction (ORR) as given in eq. (1) in alkaline media is an essential process for many technical electrochemical applications, ranging from metal‐air batteries or alkaline fuel cells to industrial‐scale chlor‐alkali electrolyzers …”

“…(1) in alkaline media is an essential process for many technical electrochemical applications, ranging from metal-air batteries or alkaline fuel cells to industrial-scale chlor-alkali electrolyzers. [1] O 2 þ 2 H 2 O þ 4 e À ! 4 OH À…”