Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

O: Fachverband Oberflächenphysik

O 58: Solid-Liquid Interfaces: Reactions and Electrochemistry II

O 58.8: Vortrag

Mittwoch, 19. März 2025, 12:15–12:30, H4

Rough Choice: Comparing 1- and 2D Representations of Electrocatalyst Morphology in Multiscale Models — •Hemanth S. Pillai, Hendrik H. Heenen, Karsten Reuter, and Vanessa J. Bukas — Fritz Haber Institute der MPG, Berlin

While electrocatalyst morphology is often used to tune product selectivity in electrochemical systems, the precise mechanism underpinning this relationship still remains elusive. Recently, we highlighted the role of morphology impacting product selectivity through a "Desorption–Re-adsorption–Reaction" mechanism [Nat. Catal. 7, 847*854 (2024)]. In particular, the catalyst morphology steers the competition between two elementary steps: either the desorption and diffusion of an intermediary byproduct or its re-adsorption and further reaction. Within such a model, morphology is captured in an effective manner via a surface roughness descriptor, however some systems may require a more explicit representation of the catalyst morphology. To assess this we employ a transport coupled kinetic model and systematically improve the representation of the catalyst from an effective one-dimensional descriptor to an explicit two-dimensional catalyst morphology. We find that deviations between the two descriptions are governed by morphological and transport parameters, i.e. diffusion length, particle size, shape, and interparticle distance. To conclude, we demonstrate that detailed morphological descriptions are only necessary within a narrow parameter window, thus providing guidance for selecting appropriate representations.

Keywords: electrocatalysis; selectivity; Morphology; mass transport; microkinetic modelling