| 摘要 |
<p>A method for fabricating a membrane-electrode assembly, and fuel cells adopting a membrane-electrode assembly formed by the method are provided. The membrane-electrode assembly fabricating method includes: coating nano-sized catalytic metal particles 23 on a proton exchange polymer membrane 24 by sputtering a catalytic metal source; coating nano-sized carbon particles 22 on the proton exchange polymer membrane 11 by arc discharging or by sputtering a carbon source to form a nanophase catalyst layer 21; and bonding electrodes to the proton exchange polymer membrane having the nanophase catalyst layer. Alternatively, nano-sized catalytic metal and nano-sized carbon particles can be coated on a proton exchanger polymer membrane to form a catalyst layer by simultaneously sputtering a catalyst metal source and a carbon source. Use of nano-sized catalytic metal and carbon particles enlarges the contact area between the catalyst layer and proton exchange polymer membrane. In addition, ultrafine catalytic metal particles are easy to penetrate into the proton exchange polymer membrane through small cavities formed on the surface. This structure of the catalyst layer allows oxidation and reduction reactions to occur at the surface of the proton exchange polymer membrane with a high efficiency. Direct coating such catalytic metal and carbon particles on the proton exchange polymer membrane reduces the amount of catalyst required, and improves catalyst utilization efficiency with improved fuel gas permeability. Furthermore, the catalyst layer adjacent to the anode is formed in a thin film form, so that cross-over of methanol can be effectively suppressed for a DMFC using the liquid fuel. <IMAGE></p> |
