The Crucial Role of Water in the Stability and Electrocatalytic Activity of Pt Electrodes

Ranninger J, Mayrhofer K, Berkes BB (2021)

Publication Type: Journal article

Publication year: 2021

Journal

Journal of Physical Chemistry C American Chemical Society

DOI: 10.1021/acs.jpcc.1c02124

Abstract

Understanding the role of water in the activity and stability of electrocatalysts is of great interest for different fundamental reactions. Investigations aiming to expand understanding of this are very challenging in aqueous electrolytes. By contrast, nonaqueous electrolytes with very well-defined water content can provide ideal conditions to better clarify the role of water in electrochemical reactions. In this paper, the dissolution and electrochemical behavior of Pt during potentiodynamic and potentiostatic measurements in methanol- and acetonitrile-based electrolytes with accurately controlled water content of <1 ppm, 100 ppm, 1000 ppm, 1%, and 10% are studied. In methanol-based electrolytes, we demonstrate the promoting effect of small amounts of water on the methanol oxidation reaction. We show the formation of surface oxide species with increasing water content in the Pt dissolution profile, which develops from a purely anodic to a predominantly cathodic dissolution, a known characteristic of aqueous electrolytes. The effect of water on the electrode stability is fundamentally different in acetonitrile-based systems: presumably, the strong adsorption of solvent molecules competes with the adsorption of water and thus inhibits the formation of an oxide layer at the surface even up to a water concentration of 1% as revealed by potentiodynamic measurements.

Authors with CRIS profile

Johanna Ranninger Lehrstuhl für Elektrokatalyse (HIERN) Karl Mayrhofer Lehrstuhl für Elektrokatalyse (HIERN)

Involved external institutions

Forschungszentrum Jülich / Research Centre Jülich (FZJ) DE Germany (DE)

How to cite

APA:

Ranninger, J., Mayrhofer, K., & Berkes, B.B. (2021). The Crucial Role of Water in the Stability and Electrocatalytic Activity of Pt Electrodes. Journal of Physical Chemistry C. https://doi.org/10.1021/acs.jpcc.1c02124

MLA:

Ranninger, Johanna, Karl Mayrhofer, and Balázs B. Berkes. "The Crucial Role of Water in the Stability and Electrocatalytic Activity of Pt Electrodes." Journal of Physical Chemistry C (2021).

BibTeX: Download