Change search
ReferencesLink to record
Permanent link

Direct link
Development of Methanol-Reforming Catalysts for Fuel Cell Vehicles
KTH, Superseded Departments, Chemical Engineering and Technology.
2003 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

Vehicles powered by proton exchange membrane (PEM) fuelcells are approaching commercialisation. Being inherently cleanand efficient sources of power, fuel cells constitute asustainable alternative to internal combustion engines to meetfuture low-emission legislation. The PEM fuel cell may befuelled directly by hydrogen, but other alternatives appearmore attractive at present, due to problems related to theproduction, transportation and handling of hydrogen.

Fuelling with an alcohol fuel, such as methanol, which isoxidised directly at the anode, offers certain advantages.However, the efficiency of the direct-methanol fuel cell (DMFC)is still significantly lower than that of the conventionalhydrogen-fuelled PEM fuel cell, due to some technical problemsremaining unsolved. Hence, indirect fuelling by a reformedliquid fuel may be the most feasible option in the early stagesof the introduction of fuel cell vehicles.

The work presented in this thesis concerns the developmentof catalysts for production of hydrogen from methanol bypartial oxidation, steam reforming or a combination thereof.The work contributes to the understanding of how thepreparation route affects catalyst morphology and howphysicochemical properties determine catalytic behaviour andreaction pathways.

The thesis is a summary of seven papers published inscientific periodicals. The first paper (Paper I) reviews thecurrent status of catalytic hydrogen generation from methanol,focusing on the fuel cell application. Paper II investigatesthe partial oxidation of methanol over Cu/ZnO catalystsprepared in microemulsion and by a conventionalco-precipitation technique. The activity for methanolconversion in the low-temperature regime is found to besignificantly higher over the former materials and the workcontinues by determining the nature of possible Cu-ZnOinteractions in the catalysts by studying their physicochemicalproperties more thoroughly (Paper III). In Paper IV, thepathways for methanol conversion via both partial oxidation andsteam reforming are elucidated.

In Paper V, partial oxidation of methanol is studied overPd/ZnO catalysts prepared by microemulsion technique and againcompared to conventional materials. This investigationdemonstrates that although possessing high methanol conversionactivity, palladium-based catalysts are not suitable forreforming in fuel cell applications due to the considerableamounts of carbon monoxide formed.

In Paper VI, methanol reforming is investigated over acommercial Cu/ZnO/Al2O3 catalyst. The mechanisms for carbonmonoxide formation and strategies for its suppression arediscussed, as well as reactor design aspects. The study alsoincludes some simple kinetic modelling. Finally, Paper VIIdescribes the optimisation of catalyst composition and processconditions to reach high hydrogen production efficiency at lowoperating temperatures and with minimum carbon monoxideformation.

Keywords:PEM fuel cells, hydrogen, methanol, reforming,(partial) oxidation, reaction pathways, carbon monoxide,catalyst, microemulsion, Cu/ZnO, Pd/ZnO, copper, redoxproperties, oxidation state

Place, publisher, year, edition, pages
Stockholm: Kemiteknik , 2003. , x, 68 p.
Trita-KET, ISSN 1104-3466 ; 181
Keyword [en]
PEM fuel cells, hydrogen, methanol, reforming, oxidation, reaction pathways, carbon monoxide
URN: urn:nbn:se:kth:diva-3669ISBN: OAI: diva2:9504
Public defence
NR 20140805Available from: 2003-12-05 Created: 2003-12-05Bibliographically approved

Open Access in DiVA

fulltext(2197 kB)2038 downloads
File information
File name FULLTEXT01.pdfFile size 2197 kBChecksum MD5
Type fulltextMimetype application/pdf

By organisation
Chemical Engineering and Technology

Search outside of DiVA

GoogleGoogle Scholar
Total: 2038 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 1289 hits
ReferencesLink to record
Permanent link

Direct link