Magnetic microparticles on electrodes: Polymer electrolyte membrane fuel cells, carbon monoxide oxidation, and transition metal complex electrochemistry

Polymer electrolyte fuel cells (PEFCs) are a promising technology that may provide clean and efficient electrical power for diverse loads ranging from residential and commercial service through electric vehicles to portable electronics. Although this technology has a very promising future, many technical limitations exist about this technology that need to be addressed prior to its widespread adoption. Limitations include cost, fuel processing and handling, and balance of plant system complexity.; Here, the incorporation of magnetic fields via polymer encapsulate magnetic microparticles into electrochemical systems to address these limitations inefficiencies is examined. Data is given that demonstrates the magnetic modification of electrodes can result in the improved electrochemical flux for transitional metal complexes, when compared to a similar nonmagnetic electrode. Studies on effects of magnetic fields impart on the oxidation of carbon monoxide to carbon dioxide at platinum catalysts are given. Magnetic modification results in the increased tolerance of these catalysts to the pacifying effects of carbon monoxide by lower the potential at which oxidation occurs and by transforming the process to diffusion controlled process from a surface stripping process. These improvements through magnetic modification can then be ported to fuel cell systems to improve system performance, catalysts tolerances to poisons, and operation on directly reformed fuel different than pure hydrogen.; Here, polymer electrolyte fuel cells are tested for enhanced performance over nonmagnetic cells while operating on directly reformed hydrocarbons (methanol and ethanol, indirectly reformed fuels containing small amounts of contaminates (carbon monoxide), and operation under self-hydrating conditions. For all systems and at certain operational conditions, an increase in performance is observed for magnetic modification. Descriptions of the methods for the construction of magnetically modified fuel cells as well as the synthesis of the modifying polymer coated magnetic particles are included.