scholarly journals Radiolytic Preparation of Electrocatalysts with Pt-Co and Pt-Sn Nanoparticles for a Proton Exchange Membrane Fuel Cell

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Sang Kyum Kim ◽  
Ji Yun Park ◽  
Soon Choel Hwang ◽  
Do Kyun Lee ◽  
Sang Heon Lee ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Photoelectron Spectroscopy ◽  
Proton Exchange Membrane ◽  
Hydrogen Oxidation ◽  
Cell Polarization ◽  
Proton Exchange ◽  
Hydrogen Oxidation Reaction ◽  
X Ray ◽  
Radiation Induced ◽  
Exchange Membrane

Nanosized Pt-Sn/VC and Pt-Co/VC electrocatalysts were prepared by a one-step radiation-induced reduction (30 kGy) process using distilled water as the solvent and Vulcan XC72 as the supporting material. While the Pt-Co/VC electrodes were compared with Pt/VC (40 wt%, HiSpec 4000), in terms of their electrocatalytic activity towards the oxidation of H2, the Pt-Co/VC electrodes were evaluated in terms of their activity towards the hydrogen oxidation reaction (HOR) and compared with Pt/VC (40 wt%, HiSpec 4000), Pt-Co/VC, and Pt-Sn/VC in a single cell. Additionally, the prepared electrocatalyst samples (Pt-Co/VC and Pt-Sn/VC) were characterized by transmission electron microscopy (TEM), scanning electron microscope (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electrochemical surface area (ECSA), and fuel cell polarization performance.

Amorphous Ni-Co-B Catalyst for Hydrolysis of NaBH4 in Alkaline Solution

2011 ◽  
Vol 675-677 ◽  
pp. 33-36
Author(s):  
Chuan Wu ◽  
Ying Bai ◽  
Feng Wu ◽  
Dan Xian Liu
Keyword(s):  
Alkaline Solution ◽  
Photoelectron Spectroscopy ◽  
Proton Exchange Membrane ◽  
Hydrogen Generation ◽  
Chemical Reduction ◽  
Heat Treating ◽  
Proton Exchange ◽  
X Ray ◽  
Bet Analysis ◽  
Exchange Membrane

Amorphous Ni-Co-B catalyst was synthesized by a chemical reduction method, and followed by a heat-treating at 100°C, then characterized by X-ray diffraction (XRD), Scanning electronic microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmetr-Teller (BET) analysis, and adopted to help accelerating hydrolysis reaction of NaBH4 alkaline solution. It is proved that the amorphous Ni-Co-B catalyst is not a simple combination of elemental Ni, Co and B, but a multiplex metal boride. It exhibits an maximum hydrogen generation rate of 210 ml/min/(g catalyst) at 100% H2 utilization, which is potentially to give a successive H2 supply for proton exchange membrane fuel cells.

Carbon corrosion of proton exchange membrane fuel cell catalyst layers studied by scanning transmission X-ray microscopy

2014 ◽  
Vol 266 ◽  
pp. 66-78 ◽  
Author(s):  
Adam P. Hitchcock ◽  
Viatcheslav Berejnov ◽  
Vincent Lee ◽  
Marcia West ◽  
Vesna Colbow ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Carbon Corrosion ◽  
X Ray ◽  
Fuel Cell Catalyst ◽  
Catalyst Layers ◽  
Scanning Transmission ◽  
Exchange Membrane

A Parametric Study of Bipolar Plate Structural Parameters on the Performance of Proton Exchange Membrane Fuel Cell

2012 ◽  
Vol 9 (5) ◽  
Author(s):  
Salar Imanmehr ◽  
Nader Pourmahmod
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Structural Parameters ◽  
Catalyst Layer ◽  
Cell Polarization ◽  
Proton Exchange ◽  
Bipolar Plates ◽  
Fuel Cell Performance ◽  
Exchange Membrane ◽  
The Impact

In this research, the impact of structural parameters of bipolar plates on the proton exchange membrane (PEM) fuel cell performance has been investigated using numerical method, and this model incorporates all the essential fundamental physical and electrochemical processes occurring in the membrane electrolyte, cathode catalyst layer, electrode backing, and flow channel, with some assumptions in each part. In formulation of this model, the cell is assumed to work under steady state conditions. Also, since the thickness of the cell is negligible compared to other dimensions, one-dimensional and isothermal approximations are used. The structural parameters considered in this paper are: the width of channels (Wc), the width of support (Ws), the number of gas channels (ng), the height of channels (hc), and the height of supports (hp). The results show that structural parameters of bipolar plates have a great impact on outlet voltage in high current densities. Also, the number of gas channels, their surface area, the contacting area of bipolar plates, and electrodes have a great effect on the rate of reaction and consequently on outlet voltage. The model predictions have been compared with the existing experimental results available in the literature, and excellent agreement has been demonstrated between the model results and the experimental data for the cell polarization curve.

scholarly journals Hydrogen Oxidation Artifact During Platinum Oxide Reduction in Cyclic Voltammetry Analysis of Low-Loaded PEMFC Electrodes

2020 ◽  
Vol 12 (1) ◽  
pp. 45-55
Author(s):  
S. Prass ◽  
J. St-Pierre ◽  
M. Klingele ◽  
K. A. Friedrich ◽  
N. Zamel
Keyword(s):  
Proton Exchange Membrane ◽  
Hydrogen Oxidation ◽  
Platinum Oxide ◽  
Proton Exchange ◽  
Cyclic Voltammograms ◽  
Reduction Peak ◽  
Oxidation Peak ◽  
Oxide Reduction ◽  
Hydrogen Oxidation Reaction ◽  
Exchange Membrane

AbstractAn artifact appearing during the cathodic transient of cyclic voltammograms (CVs) of low-loaded platinum on carbon (Pt/C) electrodes in proton exchange membrane fuel cells (PEMFCs) was examined. The artifact appears as an oxidation peak overlapping the reduction peak associated to the reduction of platinum oxide (PtOx). By varying the nitrogen (N2) purge in the working electrode (WE), gas pressures in working and counter electrode, upper potential limits and scan rates of the CVs, the artifact magnitude and potential window could be manipulated. From the results, the artifact is assigned to crossover hydrogen (H2X) accumulating in the WE, once the electrode is passivated towards hydrogen oxidation reaction (HOR) due to PtOx coverage. During the cathodic CV transient, PtOx is reduced and HOR spontaneously occurs with the accumulated H2X, resulting in the overlap of the PtOx reduction with the oxidation peak. This feature is expected to occur predominantly in CV analysis of low-loaded electrodes made of catalyst material, whose oxide is inactive towards HOR. Further, it is only measurable while the N2 purge of the WE is switched off during the CV measurement. For higher loaded electrodes, the artifact is not observed as the electrocatalysts are not fully inactivated towards HOR due to incomplete oxide coverage, and/or the currents associated with the oxide reduction are much larger than the spontaneous HOR of accumulated H2X. However, owing to the forecasted reduction in noble metal loadings of catalyst in PEMFCs, this artifact is expected to be observed more often in the future.

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