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Oxygen reduction reaction (ORR) activity and durability of carbon supported PtM (Co, Ni, Cu) alloys: Influence of particle size and non-noble metals

Paper ID Volume ID Publish Year Pages File Format Full-Text
46502 46440 2012 12 PDF Available
Title
Oxygen reduction reaction (ORR) activity and durability of carbon supported PtM (Co, Ni, Cu) alloys: Influence of particle size and non-noble metals
Abstract

Carbon supported platinum and platinum alloys (PtCo, PtNi and PtCu) for PEMFC cathodes were prepared and studied for their oxygen reduction reaction activity and durability under potential cycling at 80 °C in 0.5 M HClO4. Catalysts with different metal alloy composition and particle size were synthesized by annealing at different temperatures to discriminate between the effects of alloying and particle size on the electrocatalytic activity and durability. XRD was used for the structural characterization of pristine catalysts, while the bulk compositions were analyzed by EDS before and after durability tests. XPS was employed to determine the surface composition of selected alloys after durability tests. The particle size of the fresh and aged catalysts was determined by TEM. Rapid dealloying, particularly from non-noble metal rich alloys, was already witnessed for the alloys potentially cycled at room temperature. Significant particle growth depending on the initial particle size was observed for both Pt and Pt alloys after the durability tests. For the alloys with similar initial particle size, the initial electrocatalytic activity depends on the initial alloy composition. Although a 3-fold enhancement in the ORR activity was observed for the non-noble metal rich alloys after initial dealloying, the specific activity of Pt and Pt alloys becomes quite similar at the end of the durability tests. Annealing of Pt/C and Pt alloys at 950 °C results in catalysts with the highest specific and mass activity and with the highest stability.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Fresh non-noble metal-rich alloys show enhanced oxygen reduction activity. ► The specific activity of the aged Pt/C and PtM/C annealed at a similar temperature is quite comparable. ► The alloying effect is almost completely lost due to dissolution of about 90–95 at% non-noble metals. ► Alloy surface only consists of Pt after the durability tests, and only a weak particle-size effect remains.

Keywords
Pt alloys; ORR activity; PEMFC; Fuel cells; Durability
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Oxygen reduction reaction (ORR) activity and durability of carbon supported PtM (Co, Ni, Cu) alloys: Influence of particle size and non-noble metals
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Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis B: Environmental - Volumes 111–112, 12 January 2012, Pages 515–526
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
Online Support
Any Questions? feel free to contact us