| The direct methanol fuel cell (DMFC) is a very promising power source for low power applications. High power and energy density, low emissions, operation at or near ambient conditions, fast and convenient refueling and a potentially renewable fuel source are some of the features that make the fuel cell very promising. However, there are a few problems that have to be overcome if we are to see DMFCs in our everyday life. Two drawbacks that cause problems with the DMFC are expensive anode catalysts and poor cathode catalyst supports. For the anode catalyst, the currently used PtRu bimetallic catalyst is simply too expensive and the loading required for adequate methanol reaction kinetics is simply too high. For the cathode support, the currently used high surface area carbon has the tendency to corrode and dissolve under high voltage corrosive conditions seen at the cathode. Novel, alternative anode catalysts and cathode supports must be developed to overcome the cost and limitations of each.;The aim of this thesis is develop alternative anode catalysts and cathode support materials that will show some insight of how these problems may be begun to be solved. In order to achieve these aims, several synthesis methods were utilized in order to create the best possible materials. A fully alloyed quaternary alloy system with a high surface area is desired for the anode catalyst with reduce noble metal loading. The materials investigated for this purpose centered on PtRu based systems that incorporated materials that have shown promise in literature, namely, Ni, Ti, Sn, Co, Os. A high surface area, corrosion resistance, electronically conducting support materials is desired for the cathode support material. The materials chosen for this investigation centered on mixed metal oxides of SnTa and SnNb, based upon theoretical calculations done in our group.;The results in this thesis have shown that a SnNb2O6 foordite structure exhibits promising specific surface areas (71.5 m2/g) with an excellent corrosion resistance and a trend toward the lowest resistivity of all the support materials synthesized. A Pt 40Ru40Ni10Sn10 quaternary alloy system exhibits promising current response with an onset voltage nearly comparable to that of PtRu at 20 at% less noble metal in the alloy system.;Keywords: direct methanol fuel cell, pyrochlore, DMFC, anode, support, cathode, quaternary alloy, mixed metal oxide. |
