Jinzhen Huang^1*, Erica D. Clinton^1*, Kenneth Crossley^1*, Juliana Bruneli Falqueto^1*, Thomas J. Schmidt^1,2*, Emiliana Fabbri^1*

1 PSI Center for Energy and Environmental Sciences, CH-5232 Villigen PSI, Switzerland

2 Institute for Physical Molecular Sciences, ETH Zürich, CH-8093 Zürich, Switzerland

* Corresponding authors emails: jinzhen.huang@psi.ch, erica.clinton@psi.ch, kenneth.crossley@psi.ch, juliana.bruneli-falqueto@psi.ch, thomasjustus.schmidt@psi.ch, emiliana.fabbri@psi.ch

DOI10.24435/materialscloud:4x-f0 [version v1]

Publication date: Jan 28, 2025

How to cite this record

Jinzhen Huang, Erica D. Clinton, Kenneth Crossley, Juliana Bruneli Falqueto, Thomas J. Schmidt, Emiliana Fabbri, Uncovering the catalyst/electrolyte interfacial process by frequency dispersion of capacitance, Materials Cloud Archive 2025.23 (2025), https://doi.org/10.24435/materialscloud:4x-f0

Description

Electrochemical impedance spectroscopy (EIS) is the widely used technique to monitor the electrical properties of a catalyst under electrocatalytic conditions. Although it is extensively used for research in electrocatalysis, its effectiveness and power have not been fully harnessed to elucidate complex interfacial processes. Herein, we use the frequency dispersion parameter, n, which is extracted from EIS measurements, to describe the dispersion characteristics of capacitance and interfacial properties of Co3O4 under alkaline oxygen evolution reaction (OER) conditions. We first prove the n-value is sensitive to the interfacial electronic changes associated with Co redox processes and surface reconstruction. The n-value decreases by increasing the specific/active surface area of the catalysts. We further modify the interfacial properties by changing different components, i.e., replacing the proton with deuterium, adding ethanol as a new oxidant, and changing the cation in the electrolyte. Intriguingly, the n-value can identify different influences on the interfacial process from proton transfer, the decrease and carbon-poisoning of oxidized Co species, and the interfacial water structure. These findings convey that the frequency dispersion of capacitance is a convenient and useful method to uncover the interfacial properties under electrocatalytic conditions, which helps to advance the understanding of the interface-activity relationship.

Materials Cloud sections using this data

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File name	Size	Description
raw data for EIS SR project.xlsx MD5md5:38d7ce84a759318ef6c8f08c73c83f51	470.8 KiB	The raw data of Figures in the manusciript.

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Keywords

Frequency dispersion of capacitance Electrochemical impedance spectroscopy Catalyst/electrolyte interface interfacial capacitance Oxygen evolution reaction