TY  - JOUR
AU  - Huang, Jun
AU  - Li, Mengru
AU  - Eslamibidgoli, Mohammad J.
AU  - Eikerling, Michael
AU  - Groß, Axel
TI  - Cation Overcrowding Effect on the Oxygen Evolution Reaction
JO  - JACS Au
VL  - 1
IS  - 10
SN  - 2691-3704
CY  - Washington, DC
PB  - ACS Publications
M1  - FZJ-2021-03817
SP  - 1752-1765
PY  - 2021
AB  - The influence of electrolyte ions on the catalytic activity of electrode/electrolyte interfaces is a controversial topic for many electrocatalytic reactions. Herein, we focus on an effect that is usually neglected, namely, how the local reaction conditions are shaped by nonspecifically adsorbed cations. We scrutinize the oxygen evolution reaction (OER) at nickel (oxy)hydroxide catalysts, using a physicochemical model that integrates density functional theory calculations, a microkinetic submodel, and a mean-field submodel of the electric double layer. The aptness of the model is verified by comparison with experiments. The robustness of model-based insights against uncertainties and variations in model parameters is examined, with a sensitivity analysis using Monto Carlo simulations. We interpret the decrease in OER activity with the increasing effective size of electrolyte cations as a consequence of cation overcrowding near the negatively charged electrode surface. The same reasoning could explain why the OER activity increases with solution pH on the RHE scale and why the OER activity decreases in the presence of bivalent cations. Overall, this work stresses the importance of correctly accounting for local reaction conditions in electrocatalytic reactions to obtain an accurate picture of factors that determine the electrode activity.
LB  - PUB:(DE-HGF)16
C6  - pmid:34723278
UR  - <Go to ISI:>//WOS:000711198900024
DO  - DOI:10.1021/jacsau.1c00315
UR  - https://juser.fz-juelich.de/record/897484
ER  -