Corrosion Resistance and Catalytic Activity toward the Oxygen Reduction Reaction of CoCrFexNi (0 ≤ x ≤ 0.7) Thin FilmsShow others and affiliations
2022 (English)In: ACS Applied Energy Materials, E-ISSN 2574-0962, Vol. 5, no 9, p. 10838-10848Article in journal (Refereed) Published
Abstract [en]
Corrosion resistance and catalytic activity toward the oxygen reduction reaction (ORR) in an alkaline environment are two key properties for water recombination applications. In this work, CoCrFexNi (0 ≤ x ≤ 0.7) thin films were deposited by magnetron sputtering on polished steel substrates. The native passive layer was 2-4 nm thick and coherent to the columnar grains determined by transmission electron microscopy. The effect of Fe on the corrosion properties in 0.1 M NaCl and 1 M KOH and the catalytic activity of the films toward ORR were investigated. Electrochemical impedance spectroscopy and potentiodynamic polarization measurements indicate that CoCrFe0.7Ni and CoCrFe0.3Ni have the highest corrosion resistance of the studied films in NaCl and KOH, respectively. The high corrosion resistance of the CoCrFe0.7Ni film in NaCl was attributed to the smaller overall grain size, which leads to a more homogeneous film with a stronger passive layer. For CoCrFe0.3Ni in KOH, it was attributed to a lower Fe dissolution into the electrolyte and the build-up of a thick and protective hydroxide layer. Scanning Kelvin probe force microscopy showed no potential differences globally in any of the films, but locally, a potential gradient between the top of the columns and grain boundaries was observed. Corrosion of the films was likely initiated at the top of the columns where the potential was lowest. It was concluded that Fe is essential for the electrochemical activation of the surfaces and the catalytic activity toward ORR in an alkaline medium. The highest catalytic activity was recorded for high Fe-content films (x ≥ 0.5) and was attributed to the formation of platelet-like oxide particles on the film surface upon anodization. The study showed that the combination of corrosion resistance and catalytic activity toward ORR is possible for CoCrFexNi, making this material system a suitable candidate for water recombination in an alkaline environment.
Place, publisher, year, edition, pages
American Chemical Society , 2022. Vol. 5, no 9, p. 10838-10848
Keywords [en]
corrosion, electrocatalysis, magnetron sputtering, multicomponent thin film, ORR, water recombination, Catalyst activity, Corrosion resistance, Corrosive effects, Electrochemical corrosion, Electrochemical impedance spectroscopy, Electrolytes, Electrolytic reduction, Grain boundaries, High resolution transmission electron microscopy, Iron, Iron alloys, Oxygen, Potassium hydroxide, Sodium chloride, Ternary alloys, Thin films, Alkaline environment, Columnar grain, Magnetron-sputtering, Multicomponent thin films, Oxygen reduction reaction, Passive layer, Property, Steel substrate, Thin-films
National Category
Surface- and Corrosion Engineering
Identifiers
URN: urn:nbn:se:ri:diva-60265DOI: 10.1021/acsaem.2c01499Scopus ID: 2-s2.0-85138594235OAI: oai:DiVA.org:ri-60265DiVA, id: diva2:1702164
Note
Funding details: VINNOVA, 2009 00971, 2016-05156, 2019-04881; Funding details: Vetenskapsrådet, VR, 2021-03826; Funding text 1: This study was performed within the Competence Centre FunMat-II and was funded by the Swedish Agency for Innovation Systems (VINNOVA, grant no 2016-05156, and grant no 2019-04881). The authors would also like to acknowledge the Swedish Government Strategic Research Area in Materials Science on Functional Materials at the Linköping University (Faculty Grant SFO-Mat-LiU No. 2009 00971). The Centre in Nanoscience and Nanotechnology at LiTH (CeNano) at the Linköping University is also acknowledged. P. E. and A. l. F. also acknowledge the Swedish Research Council under project number 2021-03826.
2022-10-102022-10-102025-02-09Bibliographically approved