| A procedure was developed for the production of oxygen electrode substrates for use in solid polymer electrolyte fuel cells. The substrates will be catalyzed with platinum using Electrochemical Catalyzation, and consist of a porous backbone of hydrophobic polymer-treated carbon paper (300-500 {dollar}mu{dollar}m thick), with a region near the surface containing bonded Teflon and carbon particles. On top of this surface a thin (60-75 {dollar}mu{dollar}m thick) continuous film of Nafion solid polymer electrolyte is laid down using a solution casting technique. The fabrication technique developed gives reproducible substrates, as evaluated by surface resistance measurements, scanning electron microscopy, visual observation, and gravimetric determinations.; In addition, an apparatus capable of producing highly reproducible contact pressures was designed and constructed to measure substrate surface resistance. An Electrochemical Catalyzation cell to deposit platinum particles on the Nafion-impregnated substrates and an oxygen reduction kinetics measurement cell of evaluate oxygen electrode performance also were designed and constructed. |
