Probing the relationship between bulk and local environments to understand impacts on electrocatalytic oxygen reduction reaction

Local catalyst environments fluctuate during electrochemical reactions which significantly influences reaction efficiency and selectivity. However, elucidating fundamental relationships between local environment and electrocatalytic performance is challenging due to the difficulty in probing this lo...

Full description

Saved in:
Bibliographic Details
Published in:Journal of catalysis 2022-08, Vol.414 (C)
Main Authors: Ruggiero, Brianna N., Sanroman Gutierrez, Kenzie M., George, Jithin D., Mangan, Niall M., Notestein, Justin M., Seitz, Linsey C.
Format: Article
Language:English
Subjects:
Carbon electrocatalyst
Cation effects
Electrocatalysis
Hydrogen peroxide
INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
Local pH
Oxygen reduction reaction (ORR)
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Local catalyst environments fluctuate during electrochemical reactions which significantly influences reaction efficiency and selectivity. However, elucidating fundamental relationships between local environment and electrocatalytic performance is challenging due to the difficulty in probing this local region. Here, we study the impact of electrolyte composition on the kinetics and mechanism of the oxygen reduction reaction (ORR) for a carbon catalyst. Using a rotating ring-disk electrode equipped with an iridium oxide pH probe, we monitor changes in local pH during ORR. Additionally, we confirm that local pH changes significantly for near-neutral bulk pH and find that different cations provide variable pH-buffering, thereby modulating overall magnitude and onset of local pH changes. Overall, local pH more strongly dictates changes in mechanisms and performance, while the cation identity modulates local pH to influence these trends. This work highlights the importance relating local pH to electrocatalytic performance to further improve understanding of complex electrochemical processes
ISSN:0021-9517