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d 0 . $ Nanomanufacturing Fuel Cell MEAs Using Layer-By-Layer Assembly
Authors: Ryan C. Sekol, Marcelo Carmo, and Andr D. Taylor
Yale University, Department of Chemical Engineering, 9 Hillhouse Ave., New Haven, CT 06511
*Andr D. Taylor: HYPERLINK "mailto:Andre.Taylor@yale.edu" Andre.Taylor@yale.edu
Presentation
Short Description: High performance single-walled carbon nanotube supported Pt catalysts are synthesized in supercritical fluids and arranged into fuel cell membrane electrode assemblies (MEAs) using layer-by-layer assembly. The characterization and performance of these materials inside of a fully functioning fuel cell are described.
Keywords: Fuel Cells, PEM fuel cells, supercritical fluids, catalysts, nanostructured catalysts, carbon nanotubes, carbon fibers, Layer-by-layer, Pt Utilization
Abstract: The multifunctional requirement for thin-film fuel cell electrodes remains a significant challenge. Although nanofabrication techniques including chemical vapor deposition, colloidal assembly, atomic layer deposition and molecular beam epitaxy are currently being developed, the cost for these methods remains high. In this work, we report a new kind of fuel cell MEA constructed by using layer-by-layer (LBL) assembly. This method, developed by Decher et al., allows the build-up of polyelectrolyte multilayered films on almost any kind of surface, whatever its shape, and with a wide choice of possible polyelectrolytes ADDIN EN.CITE Lvov199350<Go to ISI>://A1993KN16000020ISI:A1993KN16000020LangmuirAssembly, Structural Characterization, and Thermal-Behavior of Layer-by-Layer Deposited Ultrathin Films of Poly(Vinyl Sulfate) and Poly(Allylamine)481-486Lvov, Y.Decher, G.Mohwald, H.langmuir-blodgett-filmsLvov, Y.
Univ Mainz,Inst Phys Chem,Welder Weg 11,W-6500 Mainz,Germany
Acad Sci Russia,Inst Crystallog,Moscow 117333,RussiaLangmuir
Langmuir29FEB1993[1]. Here we show that freestanding films of single-walled carbon nanotubes, Nafion, and polyaniline (PANI) can be constructed using this method [2].
As an electrocatalyst support, single walled carbon nanotubes (SWCNTs) have been shown to give a higher performance than standard carbon black (CB) based catalysts and we will describe a method of decorating these materials with Pt using supercritical fluids [3]. The average particle size was 7.8 nm with a range of 2.3 to 15 nm. The figure illustrates the synthesis and LBL nanomanufacturing assembly of these materials. The LBL catalyst layer consisted of 400 bi-layers of functionalized SWCNTs, Nafion, and PANI (Polyaniline). The Pt loading for this LBL thin film was 0.05 mg/cm2. The films were evaluated as both catalysts with conventional gas diffusion layers and as catalyzed gas diffusion layers. One example MEA demonstrated a peak power density of 127 mW/cm2. Although this value was less than our standard Pt/CB MEA (400 mW/ cm2) with an anode loading 0.5 mg/cm2, the Pt utilization of the LBL catalyst layer was 2,540 mW/mg compared to 800 mW/mg [4].
References
[1] For further information about this project link to or email
[2] Reilkoff, T. (2009) Construction of Fuel Cell Catalyst Layers with Nanometer Precision,
[3] Taylor, A.D., R.C. Sekol, J.M. Kizuka, S. D'Cunha, and C.M. Comisar, Fuel cell performance and characterization of 1-D carbon-supported platinum nanocomposites synthesized in supercritical fluids, Journal of Catalysis, 2008. 259(1): p. 5-16.
[4] Taylor, A.D., M. Michel, R. Sekol, J.M. Kizuka, N.A. Kotov, and L.T. Thompson, Fuel Cell MEAs (Membrane Electrode Assemblies) Created by Layer-By-Layer Electrostatic Self Assembly Techniques, Advanced Functional Materials, 2008. 18: p. 1-7.
Taylor, A. Nanomanufacturing Summit 2009
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