Unraveling the Surface Chemistry and Structure in Highly Active Sputtered Pt3Y Catalyst Films for the Oxygen Reduction Reaction
Artikel i vetenskaplig tidskrift, 2020

Platinum is the most widely used and best performing sole element for catalyzing the oxygen reduction reaction (ORR) in low-temperature fuel cells. Although recyclable, there is a need to reduce the amount used in current fuel cells for their extensive uptake in society. Alloying platinum with rare-earth elements such as yttrium can provide an increase in activity of more than seven times, reducing the amount of platinum and the total amount of catalyst material required for the ORR. As yttrium is easily oxidized, exposure of the Pt-Y catalyst layer to air causes the formation of an oxide layer that can be removed during acid treatment, leaving behind a highly active pure platinum overlayer. This paper presents an investigation of the overlayer composition and quality of Pt3Y films sputtered from an alloy target. The Pt3Y catalyst surface is investigated using synchrotron radiation X-ray photoelectron spectroscopy before and after acid treatment. A new substoichiometric oxide component is identified. The oxide layer extends into the alloy surface, and although it is not completely removed with acid treatment, the catalyst still achieves the expected high ORR activity. Other surface-sensitive techniques show that the sputtered films are smooth and bulk X-ray diffraction reveals many defects and high microstrain. Nevertheless, sputtered Pt3Y exhibits a very high activity regardless of the film's oxide content and imperfections, highlighting Pt3Y as a promising catalyst. The obtained results will help to support its integration into fuel cell systems.

X-ray spectroscopy

catalysis

thin films

platinum alloys

fuel cell catalyst

materials science

PEMFC

oxygen reduction reaction

Författare

Rosemary Brown

Chalmers, Fysik, Kemisk fysik

Mykhailo Vorokhta

Univerzita Karlova v Praze

Ivan Khalakhan

Univerzita Karlova v Praze

Milan Dopita

Univerzita Karlova v Praze

Thomas Vonderach

Danmarks Tekniske Universitet (DTU)

Tomáš Skála

Univerzita Karlova v Praze

Niklas Lindahl

Göteborgs universitet, Institutionen för fysik

Iva Matolínová

Univerzita Karlova v Praze

Henrik Grönbeck

Chalmers, Fysik, Kemisk fysik

Konstantin M. Neyman

Universitat de Barcelona

Institucio Catalana de Recerca i Estudis Avancats

Vladimír Matolín

Univerzita Karlova v Praze

Björn Wickman

Chalmers, Fysik, Kemisk fysik

ACS Applied Materials & Interfaces

1944-8244 (ISSN) 1944-8252 (eISSN)

Vol. 12 4 4454-4462

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Ämneskategorier

Oorganisk kemi

Annan kemiteknik

Annan kemi

DOI

10.1021/acsami.9b17817

PubMed

31869200

Mer information

Senast uppdaterat

2020-10-12