02096nas a2200277   4500008004100000022001400041245012500055210006900180260007400249300001200323490000700335520113600342653001901478653003801497653000801535653000801543653001001551100002101561700002301582700001501605700001401620700002201634700001801656700002201674856012201696       2008                        eng d  a0021-891X00a2(7-3) fractional factorial optimization of polybenzimidazole based membrane electrode assemblies for H-2/O-2 fuel cells0 a273 fractional factorial optimization of polybenzimidazole based  aVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDSbSPRINGERcMAY  a583-5900 v383 a<p>We describe the usefulness of a statistical fractional factorial design to obtain consistent and reproducible behavior of a membrane-electrode-assembly (MEA) based on a phosphoric acid (PA) doped polybenzimidazole (PBI) membrane, which allows a H-2/O-2 fuel cell to operate above 150 degrees C. Different parameters involved during the MEA fabrication including the catalyst loading, amount of binder, processing conditions like temperature and compaction load and also the amount of carbon in the gas diffusion layers (GDL) have been systematically varied according to a 2(7-3) fractional factorial design and the data thus obtained have been analyzed using Yates's algorithm. The mean effects estimated in this way suggest the crucial role played by carbon loading in the gas diffusion layer, hot compaction temperature and the binder to catalyst ratio in the catalyst layer for enabling continuous performance. These statistically designed electrodes provide a maximum current density and power density of 1,800 mA cm(-2) and 280 mW cm(-2), respectively, at 160 degrees C using hydrogen and oxygen under ambient pressure.</p>10aCarbon loading10aFractional factorial optimization10aMEA10aPBI10aPEMFC1 aKannan, Ramaiyan1 aIslam, Md., Nazrul1 aRathod, D.1 aVijay, M.1 aKharul, Ulhas, K.1 aGhosh, P., C.1 aVijayamohanan, K.  uhttp://library.ncl.res.in/content/27-3-fractional-factorial-optimization-polybenzimidazole-based-membrane-electrode-003338nas a2200253   4500008004100000022001400041245019100055210006900246260010600315300001400421490000700435520231200442653003202754653001002786653003002796653001702826653001002843100002402853700002502877700001902902700002202921700002402943856011702967       2010                        eng d  a0013-468600aPt-MoOx-carbon nanotube redox couple based electrocatalyst as a potential partner with polybenzimidazole membrane for high temperature polymer electrolyte membrane fuel cell applications0 aPtMoOxcarbon nanotube redox couple based electrocatalyst as a po  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcMAR  a2878-28870 v553 a<p>A redox couple based electrocatalyst comprising of Pt-Multi Wall Carbon NanoTube (Pt-MWCNT) promoted with molybdenum oxide (MoOx, 2 &lt; x &lt; 3) nanoparticles was prepared. The objective was to effectively organize the Pt-MoOx interface on the smooth MWCNT surface to overcome the practical difficulties associated with establishing such interface with Pt dispersed on carbon morphologies possessing surface irregularities. The present study revealed the importance of stringent controlling of the additive level for maintaining a balanced bifunctional behavior of the catalyst combination through the synergistic effects by the components and the need of a proton conducting membrane operable at high temperature to get better output from the Polymer Electrolyte Membrane Fuel Cell (PEMFC) systems. An indigenously developed polybenzimidazole (PBI) membrane was used to fabricate a membrane electrode assembly (MEA) as it can be operated at higher temperatures compared to that of Nafion membranes. MoOx additive level was carefully controlled by monitoring the active Pt area by cyclic voltammetry. All prepared electrocatalysts were characterized by using HRTEM, XRD and XPS to get information on dispersion and morphology, crystalinity and oxidation state of different elements, respectively. The system prepared with 5% MoOx addition with respect to Pt (hereafter Pt-MoOx(5%)-MWCNT) displayed balanced active Pt area and excellent oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) activities. Rotating Disk Electrode (ROE) system was extensively utilized to understand the ORR kinetics and the favorable role of MoOx as the promoter in the reaction. The kinetic current (j(k)) measured at 0.02 V vs. Hg/Hg2SO4 electrode from the Koutecky-Levich plots was 9 times higher and the apparent activation energy during single cell evaluation was 27 kJ/mol lower for the MoOx promoted system, compared to the system without the additive. A higher operating temperature significantly favored the cell performance by a combined effect of enhancement in proton conductivity of the PBI membrane and possible kinetic benefit by the well postulated oxygen spill over effect by the MoOx type systems in some combinations involving such systems. (C) 2010 Elsevier Ltd. All rights reserved.</p>10aMethanol oxidation reaction10aMWCNT10aoxygen reduction reaction10aPBI membrane10aPEMFC1 aVellacheri, Ranjith1 aUnni, SreeKuttan, M.1 aNahire, Sandip1 aKharul, Ulhas, K.1 aKurungot, Sreekumar  uhttp://library.ncl.res.in/content/pt-moox-carbon-nanotube-redox-couple-based-electrocatalyst-potential-partner-0