Modeling the Influence of Electrolyte Distribution in Silver Gas Diffusion Electrodes for CO2 Electroreduction

• DOI: 10.1149/ma2023-01261727mtgabs
• Publication Date: 2023-09-19T22:51:10Z
• Authors: Jens Osiewacz; Marco Löffelholz; Thomas Turek
• Keywords: Saturation (graph theory); Gaseous diffusion

The chemical industry has been increasingly focusing on reducing CO 2 emissions in recent years. One promising way to do this is via electroreduction, a technology that does not only reduce but also allows be used as source of carbon for making commodity chemicals. A key efficient electroreduction the electrolyte management inside porous system gas diffusion electrodes (GDEs). Flooding can severely hinder mass transfer and thereby prevent reduction, giving rise parasitic hydrogen evolution reaction [1]. Although measurement saturation possible through methods like synchrotron radiography, these measurements are highly expensive, thus always readily available [2]. Modeling help here better understand influence saturation, predict measures improving process. In most electrolysis models literature, fixed parameter [3,4]. This assumption hold true, effects electro-wetting change wetting behavior GDE different operating conditions. new modeling approach, correlations between capillary pressure well contact angle potential introduced, description changes possible. These gained from pore network simulations electrode material reconstructed FIB-SEM measurements. implemented one dimensional continuum model includes discretized balance spaces liquid phase GDE, ideally mixed bulk respective sides electrode, boundary layers electrode. Homogeneous reactions carbonate buffer electrochemical considered. Transport species calculated using Maxwell-Stefan diffusion, migration field resulting Nernst-Planck equation, flow according Darcy’s law. Additionally processes dissolution evaporation water validated with experimental data electrolysis, enabling insights into elucidating transfer. [1] Bienen, F., Paulisch, M. C., Mager, T., Osiewacz, J., Nazari, M., Osenberg, Ellendorff, B., Turek, Nieken, U., Manke, I., & Friedrich, K. A., Investigating electrowetting silver‐based gas‐diffusion during oxygen reduction optical methods. Electrochemical Science Advances (2022) e2100158. [2] Hoffmann, H., Gebhard, Kutter, Hilger, Arlt, Kardjilov, N., Beckmann, Markötter, Luik, Roth, Development Modular Operando Cell X-ray Imaging Strongly Absorbing Silver-Based Gas Diffusion Electrodes. Journal Society 169 044508. [3] Löffelholz, Lüken, Perrey, K., Bulan, at silver TFFA approach. Chemical Engineering 435 134920. [4] Weng, L.-C., Bell, A. Weber, Z., gas-diffusion reduction. Physical Chemistry Physics 25 (2018) 16973–16984. Figure 1