Effects of a Co-Reactant Redox Behavior on the AC Impedance Response of the ORR
Abstract
Electrochemical impedance spectroscopy (EIS) is a useful, in-situ, minimally invasive tool to diagnose reactions. A small sinusoidal AC signal perturbation in current or voltage is applied to the electrochemical charging or discharging (DC current) processes and the response signal is collected for impedance/phase gain analysis. Reaction kinetics and reactant transport have different characteristic time constants, and are evaluated by separating impedance spectra into frequency ranges representative of electrochemical processes that are simulated by electrical circuit elements such as capacitors and resistors (1). The co-adsorption of other electrochemically active species present in reactant streams affect the impedance responses of the main electrochemical reaction. The coverage resistance, the change in reaction rate induced by the modification in other species coverage, is either positive or negative and depends on the co-reactant reaction.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 01, 2017
- Source ID
- 10.1149/ma2017-02/33/1457
Entities
People
- Jean St-pierre
- Junjie Ge
- Yunfeng Zhai