Casey E. Beall¹, Emiliana Fabbri^1*, Adam H. Clark¹, Nur Sena Yüzbasi², Thomas Graule², Thomas J. Schmidt^1,3

1 Paul Scherrer Institute (PSI), 5232 Villigen PSI, Switzerland

2 Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Switzerland

3 Laboratory of Physical Chemistry, ETH Zürich, 8093 Zürich, Switzerland

* Corresponding authors emails: emiliana.fabbri@psi.ch

DOI10.24435/materialscloud:qc-ew [version v1]

Publication date: May 23, 2023

How to cite this record

Casey E. Beall, Emiliana Fabbri, Adam H. Clark, Nur Sena Yüzbasi, Thomas Graule, Thomas J. Schmidt, Influence of carbon on the dynamic changes in Co oxidation state of Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ perovskite catalyst during the oxygen reduction and evolution reactions, Materials Cloud Archive 2023.79 (2023), doi: 10.24435/materialscloud:qc-ew.

Description

Carbon is often used as a conductive additive in catalyst layers to increase conductivity and catalytic activity. However, the effect of carbon addition to perovskites on the oxygen reduction (ORR) and oxygen evolution (OER) reactions is convoluted. In this work, composites of perovskite Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ (BSCF) and conductive additives, carbon and indium doped tin oxide are compared. It is found that the conductive additives have differing effects on the ORR and OER activities and cobalt redox behavior, with carbon having a much more significant effect. In order to elucidate further these differences between BSCF and BSCF/Carbon, operando X-ray absorption spectroscopy (XAS) is measured simultaneously with cyclic voltammetry into the ORR and OER regions and the continuous changes in the Co oxidation state are observed with high time resolution. We theorize that carbon is enhancing the Co redox activity and as a result, the ORR and OER activities are likewise improved.

Materials Cloud sections using this data

Files

File name	Size	Description
Conductivity.zip MD5md5:7ef8a518ce7376121be48e21124a5a0f	3.0 KiB	Conductivity Raw Data
Electrochemistry.zip MD5md5:505c345e29308983093443ac04baffcb	595.4 KiB	Electrochemistry Raw Data
XAS.zip MD5md5:3d07749560976f61cf655a36d7e64c4f	454.9 MiB	X-ray absorption spectroscopy (XAS) Raw Data
XRD.zip MD5md5:f8434f440542b03a99886e7852251b4a	11.1 KiB	XRD Raw Data

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External references

Keywords

ORR OER electrocatalysis alkaline cobalt XAS BSCF