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Electrochemical promotion of CO combustion over Pt/YSZ under high vacuum conditions

Paper ID Volume ID Publish Year Pages File Format Full-Text
46702 46445 2012 5 PDF Available
Title
Electrochemical promotion of CO combustion over Pt/YSZ under high vacuum conditions
Abstract

Electrochemical promotion of CO combustion over Pt/YSZ was investigated under high vacuum conditions. A galvanostatic step was coupled to mass spectrometric gas analysis using an electrochemical mass spectrometric monitoring device. Non-Faradaic electrochemical promotion of catalysis took place at 300 °C while only electrochemical oxidation was observed at 400 °C. Oxygen evolution measurements revealed that electrochemical promotion is related to the thermodynamically stable PtOx species over the Pt/gas interface. The polarization time and O2 pressure show strong influence on the relaxation transient upon current interruption. We propose that during anodic polarization, PtOx is first formed at the Pt/YSZ interface. With prolonged polarization time, the formed PtOx either migrates over the Pt/gas interface inducing electrochemical promotion or diffuses into the Pt bulk leading to the oxygen storage. After polarization, the stored O species is released and acts as sacrificial promoter causing the persistent electrochemical promotion effect.

Graphical abstractOxygen evolution and catalytic rate measurements under high vacuum conditions show that electrochemical promotion is related to PtOx, which is stable at 300 °C but thermodynamically unstable at 400 °C. During anodic polarization, PtOx is first formed at the Pt/YSZ interface. With prolonged polarization time, the formed PtOx either migrates over the Pt/gas interface inducing electrochemical promotion or diffuses into the Pt bulk leading to the oxygen storage. After polarization, the stored O species is released and acts as sacrificial promoter causing the persistent electrochemical promotion effect.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► EPOC of CO oxidation is investigated under high vacuum conditions. ► O2 evolution and catalytic reveal that EPOC is related to stable PtOx. ► Polarization time and O2 pressure strongly influence the oxygen storage. ► O2 is released after polarization and acts as sacrificial promoter.

Keywords
Electrochemical promotion; Pt/YSZ; Oxygen storage; High vacuum; Persistent electrochemical promotion
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Electrochemical promotion of CO combustion over Pt/YSZ under high vacuum conditions
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Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis B: Environmental - Volumes 113–114, 22 February 2012, Pages 250–254
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
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Any Questions? feel free to contact us