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Article Citation - WoS: 20Citation - Scopus: 21Electrochemical Behaviour and Electrochemical Polymerization of Fluoro-Substituted Anilines(Wiley, 2002) Cihaner, A; Önal, AMThe electrochemical behaviour of three fluoro-substituted aniline monomers, 2-fluoroaniline (2FAN), 3-fluoroaniline (3FAN) and 4-fluoroaniline (4FAN), was investigated in aqueous acidic and organic media by means of cyclic voltammetry (CV) studies. Constant potential electrolysis (CPE) of the monomers in acetonitrile-water mixture (1: 1 by volume) using NaClO4 as supporting electrolyte yielded soluble polymers. The mechanism of electrochemical polymerization was investigated using in situ electron spin resonance (ESR) and in situ UV-VIS spectroscopic techniques for one of the monomers (4FAN). Both CV and in situ LTV-VIS measurements indicated that the polymers obtained are in the emeraldine base form. In situ ESR studies indicated that electrochemical polymerization involves a radical-cation as an intermediate. Characterization of polymer products have been carried out using FTIR and NMR spectroscopic techniques, and thermal behaviour was studied using differential scanning calorimetry (DSC). It was found that conductivity can be imparted to assynthesized polyfluoroanilines via iodine doping. (C) 2002 Society of Chemical Industry.Article Citation - WoS: 26Citation - Scopus: 27Performance of an Ht-Pemfc Having a Catalyst With Graphene and Multiwalled Carbon Nanotube Support(Wiley, 2019) Alpaydin, Guvenc Umur; Devrim, Yilser; Colpan, C. OzgurIn this study, the effect of multiwalled carbon nanotube and graphene nanoplatelet-based catalyst supports on the performance of reformate gas-fed polybenzimidazole (PBI)-based high-temperature proton exchange membrane fuel cell (HT-PEMFC) was investigated. In addition, the effect of several microwave conditions on the performance of the Pt-Ru/multiwalled carbon nanotube (MWCNT)-graphene nanoplatelet (GNP) catalyst was assessed. Through X-ray diffraction, thermal gravimetric analysis, transmission electron microscopy, scanning electron microscopy, and energy dispersive spectroscopy, the catalysts' chemical structure and morphology were characterized. Cyclic voltammetry analysis was used for the electrochemical characterization of catalysts through an electrochemical cell with three electrodes connected to a potentiostat. The results showed that the best performing catalyst is the catalyst produced using 800-W power for 40 seconds. The electrochemically active surface area values of this catalyst ranged from 54 to 45 m(2)/g. Single-cell performance tests of the HT-PEMFC were then carried out. In these tests, reformate gas mixture, consisting of H-2, CO2, and CO, was fed to the anode side at 160 degrees C without humidification. These tests for the best performing catalyst yielded peak power density of 0.280 W/cm(2) and current density (at 0.6 V) of 0.180 A/cm(2) in the H-2/air environment and peak power density of 0.266 W/cm(2) and current density (at 0.6 V) of 0.171 A/cm(2) in the reformate gas/air environment. As a result of the experiments, it was found that Pt-Ru/MWCNT-GNP hybrid material is a suitable catalyst for HT-PEMFC.
