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Direct support mixture painting, using Pd(0) organo-metallic compounds - an easy and environmentally sound approach to combine decoration and electrode preparation for fuel cells
Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik. Department of Chemical and Biological Engineering, Chalmers University of Technology, Sweden.
Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
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2014 (Engelska)Ingår i: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 2, nr 48, s. 20973-20979Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

An inventive, fast and straight-forward approach for the direct preparation of fuel cell electrodes has been developed and tested. Our approach avoids long catalyst preparation and post-synthesis treatment. It reduces the use of chemicals and thereby concomitantly lowers the environmental impact and improves cost efficiency. It combines decoration of the support by palladium nanoparticles with electrode preparation through a simple one-step ink-painting and annealing process. Composites have been investigated by high resolution transmission electron microscopy, scanning electron microscopy, and Xray diffraction. Crystalline particles are well-attached and well-distributed on the support. Particles are of few nanometers in size and spherical for decorated Vulcan whereas they are larger and irregularly shaped for decorated helical carbon nanofibers (HCNFs). Electrodes with a metal loading of 0.8 mg cm(-2) have been tested in a direct formic acid fuel cell. Both the Vulcan and the HCNF electrodes show a similar and high power output of up to 120 mW mg(-1). They also show similar performances in deactivation experiments conducted at 200 mA cm(-2) even when using only high purity grade formic acid. After deactivation the electrodes show no structural damage, making them superior to most commercial catalysts. The electrodes can be completely regenerated to initial activity by simple treatment with water. The easy regeneration process indicates that CO-adsorption on the fuel cell anode catalyst is not the main poisoning mechanism responsible for electrode degeneration.

Ort, förlag, år, upplaga, sidor
2014. Vol. 2, nr 48, s. 20973-20979
Nationell ämneskategori
Energisystem
Identifikatorer
URN: urn:nbn:se:umu:diva-98461DOI: 10.1039/c4ta04273eISI: 000345531200070Scopus ID: 2-s2.0-84911864610OAI: oai:DiVA.org:umu-98461DiVA, id: diva2:785194
Tillgänglig från: 2015-02-02 Skapad: 2015-01-22 Senast uppdaterad: 2019-04-29Bibliografiskt granskad
Ingår i avhandling
1. Innovations in nanomaterials for proton exchange membrane fuel cells
Öppna denna publikation i ny flik eller fönster >>Innovations in nanomaterials for proton exchange membrane fuel cells
2019 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Alternativ titel[sv]
Utveckling av nanomaterial för polymerelektrolytbränsleceller
Abstract [en]

Hydrogen technologies are rapidly receiving increased attention as it offers a renewable energy alternative to the current petroleum-based fuel infrastructure, considering that continued large-scale use of such fossil fuels will lead to disastrous impacts on our environment. The proton exchange membrane fuel cell should play a significant role in a hydrogen economy since it enables convenient and direct conversion of hydrogen into electricity, thus allowing the use of hydrogen in applications particularly suited for the transportation industry. To fully realize this, multiple engineering challenges as well as development of advanced nanomaterials must however be addressed.

In this thesis, we present discoveries of new innovative nanomaterials for proton exchange membrane fuel cells by targeting the entire membrane electrode assembly. Conceptually, we first propose new fabrication techniques of gas diffusion electrodes based on helical carbon nanofibers, where an enhanced three-phase boundary was noted in particular for hierarchical structures. The cathode catalyst, responsible for facilitating the sluggish oxygen reduction reaction, was further improved by the synthesis of platinum-based nanoparticles with an incorporated secondary metal (iron, yttrium and cobalt). Here, both solvothermal and high-temperature microwave syntheses were employed. Catalytic activities were improved compared to pure platinum and could be attributed to favorably shifted oxygen adsorption energies as a result of successful incorporation of the non-precious metal. As best exemplified by platinum-iron nanoparticles, the oxygen reduction reaction was highly sensitive to both metal composition and the type of crystal structure. Finally, a proton exchange membrane based on fluorine and sulfonic acid functionalized graphene oxide was prepared and tested in hydrogen fuel cell conditions, showing improvements such as lowered hydrogen permeation and better structural stability. Consequently, we have demonstrated that there is room for improvement of multiple components, suggesting that more powerful fuel cells can likely be anticipated in the future.

Ort, förlag, år, upplaga, sidor
Umeå: Umeå University, 2019. s. 88
Nyckelord
Fuel Cells, Membrane Electrode Assembly, Oxygen Reduction Reaction, Platinum alloy catalyst, Nanoparticles, Gas Diffusion Electrode, Proton Exchange Membrane
Nationell ämneskategori
Energisystem Nanoteknik Annan materialteknik Annan kemiteknik Den kondenserade materiens fysik
Forskningsämne
materialvetenskap; fasta tillståndets fysik
Identifikatorer
urn:nbn:se:umu:diva-158501 (URN)978-91-7855-044-9 (ISBN)
Disputation
2019-05-28, N460, Naturvetarhuset, Umeå, 10:15 (Engelska)
Opponent
Handledare
Tillgänglig från: 2019-05-07 Skapad: 2019-04-29 Senast uppdaterad: 2019-05-06Bibliografiskt granskad

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