Date of Award
Master of Science
Michael D. Best, Thomas A. Zawodzinski
The Oxygen Reduction Reaction (ORR) taking place at the cathode of a fuel cell is catalyzed by Platinum due to its high activity and good stability in the acidic polymer electrolyte membrane fuel cell (PEMFC) environment. Due to its prohibitive cost and limited reserves, it is not practical to use Pt as the catalyst for mass commercialization. By taking inspiration from nature, we have devised a series of catalysts which will help in replacing Platinum at the cathode in commercial fuel cells. To gauge the activity of various ligands, metal salts and carbon surfaces, adsorbed experiments were carried out and these samples were tested for ORR activity. In order to improve the stability of these catalysts, covalent binding of 3,5-diamino-1,2,4-triazole to the carbon surface was successfully attempted. Copper (II) salts and Cobalt (III) salts were used as metal chelates to generate the M-N centers which are known to be catalytically active. Pyrolysis of the Cobalt (III) complexes was performed to enhance the catalytic activity. Triazolo-hemiphthalocyanines were synthesized on the carbon surface and complexed with different metal chelates, pyrolyzed and tested for activity after pyrolysis. The triazole-hemiphthalocyanines had an onset potential of 0.84 V, which is very close to the commercial Pt/C electrode (0.9 V).
Dabke, Chinmay Nagesh, "Utility of 1,2,4-triazoles as Catalysts for ORR in Fuel Cells. " Master's Thesis, University of Tennessee, 2012.
Available for download on Saturday, August 31, 2013