High resolution electronic absorption and extinction coefficients of the allyl radical

Electronic absorption spectra in the 210-250 nm region, were reported for the allyl radical in the vapor phase and subsequent reactions have been investigated by kinetic spectroscopy and gas-liquid chromatography. Extinction coefficients are calculated for the strong absorption bands of the allyl free radical by measured rate constants at room temperature. (C) 2002 Elsevier Science B.V. All rights reserved

catalyst support for fuel cell applications

Polypyrrole (PPy)/Carbon composites were synthesized by in situ chemical oxidative polymerization of pyrrole monomer on carbon black. Effects of polymerization temperature (either 0 degrees C or 25 degrees C) and different dopants including p-toluenesulfonic acid (p-TSA) and sodium dodecyl sulfate (SDS) on the properties of the composites were investigated. The synthesized composites were characterized by XRD, FTIR and TGA. Electrical conductivities of the composites were determined by using four-point probe technique. Electrochemical oxidation characteristics of the synthesized PPy/Carbon composites were investigated by cyclic voltammetry via potential holding experiments. The PPy/Carbon composites synthesized at 0 degrees C and with p-TSA as dopant showed the best oxidation resistance than carbon and other composites. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved

PtNi-Decorated Metal Oxide Electrodes for Borohydride Fuel Cells

PtNi nanoparticles are grafted onto three different metal oxide supports, namely MnO2, MnO2+ TiO2 and MnO2+ NiO. Subsequently, their activity for oxygen reduction reaction (ORR) and borohydride oxidation reaction (BOR) in alkaline media was studied using voltammetric techniques. The dependence of electrocatalysts behavior on reaction conditions, such as electrolyte temperature, was also evaluated. ORR and BOR kinetic parameters, namely Tafel slopes, kinetic current densities, and activation energies, were determined from the obtained data in order to compare the performance of the three electrocatalysts prepared. These results show that PtNi anchored on metal oxide supports possess electrocatalytic activity for ORR and BOR in alkaline media, which suggests potential application of these materials in direct borohydride fuel cells