Using layer-by-layer assembly of polyaniline fibers in the fast preparation of high performance fuel cell nanostructured membrane electrodes.
Membrane electrode assemblies (MEA) for fuel cells require optimization of their nanoscale organization to reach performance parameters, which include enhanced power density, increased catalyst utilization and reduced cost. We applied sprayed layer-by-layer assembly to produce a high activity MEA for H(2)/O(2) fuel cells from polyaniline fibers (PANI-F). This technique produces "fast-prepared" membranes with nanoscale structure, which allows to adequately address specific tuning of their porosity, platinum loading, electronic conductivity, and proton conductivity. Pt nanoparticles were attached to the PANI-F in a reaction of selective heterogeneous nucleation. After functionalization, Pt/PANI-F were assembled with Nafion. Microscopic investigation revealed that functionalized polyaniline fibers formed a highly porous yet tight network of interpenetrating conductors connected to the catalytic Pt particles. The Pt/PANI-F LBL ultrathin MEA demonstrated a power densitiy of 63 mW cm(-2) and yielded a Pt utilization of 437.5 W g(-1) Pt which is comparable to the traditional fuel cell using carbon black as Pt support. Moreover, the amount of Pt used in this work is almost 2 times lower than for usual carbon-supported Pt catalysts.
Institute for Materials Science, TU Darmstadt, D-64287, Darmstadt, Germany.
Marc
M
Michel
Frank
F
Ettingshausen
Frieder
F
Scheiba
André
A
Wolz
Christina
C
Roth
D000814:Aniline Compounds / Q000737:chemistry*; D002384:Catalysis; D011211:Electric Power Supplies; D004563:Electrochemistry; D004566:Electrodes; D005465:Fluorocarbon Polymers / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D010316:Particle Size; D010984:Platinum / Q000737:chemistry; D013818:Thermogravimetry; D014961:X-Ray Diffraction
D000814:Aniline Compounds; D005465:Fluorocarbon Polymers; D008567:Membranes, Artificial; C416807:polyaniline; C040402:perfluorosulfonic acid; D010984:Platinum; D006859:Hydrogen; D010100:Oxygen