Reduction Kinetics of iron ore pellets and the effect of Binders

Reduction of Iron Ore Pellets with a particular percentage of binders i.e. 2% of Dextrine and 2% of Bentonite was carried out for the temperature range 900 to 1050°C. In reduction kinetic study the most satisfactory model was to taken, the slope of the initial linear region of fractional reduction vs. time curve was measured, which gives the rate constant (k). Ln k vs. 1/T plots were straight line from which Activation Energy was calculated. Pellets having different percentages of binders were reduced and compared to find the effect of binder

Mesoporous Carbon and Poly(3,4-ethylenedioxythiophene) Composite as Catalyst Support for Polymer Electrolyte Fuel Cells

In situ polymerization of 3,4-ethylenedioxythiophene with sol–gel-derived mesoporous carbon (MC) leading to a new composite and its subsequent impregnation with Pt nanoparticles for application in polymer electrolyte fuel cells (PEFCs) is reported. The composite exhibits good dispersion and utilization of platinum nanoparticles akin to other commonly used microporous carbon materials, such as carbon black. Pt-supported MC–poly(3,4-ethylenedioxythiophene) (PEDOT) composite also exhibits promising electrocatalytic activity toward oxygen reduction reaction, which is central to PEFCs. The PEFC with Pt-loaded MC-PEDOT support exhibits 75% of enhancement in its power density in relation to the PEFC with Pt-loaded pristine MC support while operating under identical conditions. It is conjectured that Pt-supported MC–PEDOT composite ameliorates PEFC performance/ durability on repetitive potential cycling

PEDOT–PSSA as an alternative support for Pt electrodes in PEFCs

Poly (3,4-ethylenedioxythiophene) (PEDOT) and poly (styrene sulphonic acid) (PSSA) supported platinum (Pt) electrodes for application in polymer electrolyte fuel cells (PEFCs) are reported. PEDOT–PSSA support helps Pt particles to be uniformly distributed on to the electrodes, and facilitates mixed electronic and ionic (H+-ion) conduction within the catalyst, ameliorating Pt utilization. The inherent proton conductivity of PEDOT–PSSA composite also helps reducing Nafion content in PEFC electrodes. During prolonged operation of PEFCs, Pt electrodes supported onto PEDOT–PSSA composite exhibit lower corrosion in relation to Pt electrodes supported onto commercially available Vulcan XC-72R carbon. Physical properties of PEDOT– PSSA composite have been characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. PEFCs with PEDOT–PSSA-supported Pt catalyst electrodes offer a peak power-density of 810 mW cm–2 at a load current-density of 1800 mA cm–2 with Nafion content as low as 5 wt.% in the catalyst layer. Accordingly, the present study provides a novel alternative support for platinized PEFC electrodes

A solid-polymer-electrolyte direct methanol fuel cell (DMFC) with Pt–Ru nanoparticles supported onto poly(3,4-ethylenedioxythiophene) and polystyrene sulphonic acid polymer composite as anode

Nano-sized Pt–Ru supported onto a mixed-conducting polymer composite comprising poly(3,4-ethylenedioxythiophene)-polystyrene sulphonic acid (PEDOT–PSSA) is employed as anode in a solid-polymer-electrolyte direct methanol fuel cell (SPE–DMFC) and its performance compared with the SPE–DMFC employing conventional Vulcan XC-72R carbon supported Pt–Ru anode. Physical characterization of the catalyst is conducted by Fourier-transform infra-red (FTIR) spectroscopy, X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Energy dispersive X-ray analysis (EDAX) in conjunction with cyclic voltammetry and chronoamperometry. The study suggests that PEDOT–PSSA to be a promising alternative catalyst-support-material for SPE–DMFCs

Durability of Pt/C and Pt/MC-PEDOT Catalysts under Simulated Start-Stop Cycles in Polymer Electrolyte Fuel Cells

A composite of mesoporous carbon (MC) with poly(3,4-ethylenedioxythiophene) (PEDOT) is studied as catalyst support for platinum nanoparticles. The durability of commercial Pt/carbon and Pt/MC-PEDOT as cathode catalyst is investigated by invoking air-fuel boundary at the anode side so as to foster carbon corrosion at the cathode side of a polymer electrolyte fuel cell (PEFC). Pt/MC-PEDOT shows higher resistance to carbon corrosion in relation to Pt/C. Electrochemical techniques such as cyclic voltammetry (CV) and impedance measurements are used to evaluate the extent of degradation in the catalyst layer. It is surmised that the resistance of MC-PEDOT as catalyst support toward electrochemical oxidation makes Pt/MC-PEDOT a suitable and stable cathode catalyst for PEFCs

Catalytic activity of Pt anchored onto graphite nanofiber-poly (3,4-ethylenedioxythiophene) composite toward oxygen reduction reaction in polymer electrolyte fuel cells

The potential of graphite nanofiber (GNF)-Poly(3,4-ethylenedioxythiophene) (PEDOT) composite is explored as a catalyst support for polymer electrolyte fuel cells (PEFCs). Due to electron accepting nature of GNF and electron donating nature of PEDOT, the monomer EDOT adsorbs on the surface of GNF due to strong electrostatic π-π interaction. Pt nanoparticles are impregnated on GNF-PEDOT composite by ethylene glycol reduction method and their effects on electro catalytic activity for oxygen reduction reaction (ORR) are systemically studied. Pt particles supported on GNF-PEDOT with catalyst loading of 0.2 mg cm-2 exhibit a peak power density of 537 mW cm-2 at a load current density of 1120mAcm-2, while it was only 338 mW cm -2 at a load current density of 720 mA cm-2 in case of Pt particles supported on pristine GNF. The superior behavior of GNF-PEDOT supported Pt catalyst could be exclusively credited to the high graphitic nature of GNF and their mild functionalization with PEDOT increasing uniform dispersion of Pt. Indeed, the non-destructive functionalization of GNF with conducting polymer, such as PEDOT, makes them promising catalyst-supports for PEFCs. Crown Copyright © 2013 Published by Elsevier Ltd. All rights reserved.

Catalytic activity of Pt anchored onto graphite nanofiber-poly(3,4-ethylenedioxythiophene) composite toward oxygen reductionreaction in polymer electrolyte fuel cells

The potential of graphite nanofiber (GNF)–Poly(3,4-ethylenedioxythiophene) (PEDOT) composite isexplored as a catalyst support for polymer electrolyte fuel cells (PEFCs). Due to electron accepting natureof GNF and electron donating nature of PEDOT, the monomer EDOT adsorbs on the surface of GNF dueto strong electrostatic �–� interaction. Pt nanoparticles are impregnated on GNF–PEDOT composite byethylene glycol reduction method and their effects on electro catalytic activity for oxygen reductionreaction (ORR) are systemically studied. Pt particles supported on GNF–PEDOT with catalyst loading of0.2 mg cm−2exhibit a peak power density of 537 mW cm−2at a load current density of 1120 mA cm−2,while it was only 338 mW cm−2at a load current density of 720 mA cm−2in case of Pt particles supportedon pristine GNF. The superior behavior of GNF–PEDOT supported Pt catalyst could be exclusively cred-ited to the high graphitic nature of GNF and their mild functionalization with PEDOT increasing uniformdispersion of Pt. Indeed, the non-destructive functionalization of GNF with conducting polymer, such asPEDOT, makes them promising catalyst-supports for PEFCs