scholarly journals Impact of CeO2 Nanoparticle Morphology: Radical Scavenging within the Polymer Electrolyte Membrane Fuel Cell

2021 ◽  
Author(s):  
Yejin Yun ◽  
Aniket Kumar ◽  
Jaewoon Hong ◽  
Sun-Ju Song
Keyword(s):  
Polymer Electrolyte ◽  
Lattice Structure ◽  
Polymer Electrolyte Membrane ◽  
Radical Scavenging ◽  
Active Phase ◽  
Active Surface ◽  
Nafion Membrane ◽  
Hydrothermal Route ◽  
Electrolyte Membrane ◽  
Scavenging Efficiency

Abstract This paper reports a systematic investigation of the radical scavenging behaviour of ceria with different morphological shapes inside Nafion membrane. All the ceria nanostructure is synthesized using a template-free hydrothermal route. Distinct crystal planes of CeO2 have different numbers of broken bonds and reaction sites having different surface energies. So, the preparation of CeO2 with various uncovered planes may enhance its scavenging activity. The crystal structure, morphology, and lattice structure are investigated using transmission electron microscopy (TEM), and X-ray diffraction (XRD). The results show that the radical scavenging efficiency of ceria strongly depends on the active surface plane, and decreases in the following order: nanorods > nanocube > nanosphere. Furthermore, the concentrations of surface oxygen vacancies and lattice cerium (III) are correlated with the morphology of the nanoparticles. This relationship clarifies the vital scavenging mechanism of CeO2 that mitigates degradation inside the polymer electrolyte membrane. This is because the inherent lattice strain on the active planes of nanosized ceria with different shapes affects their surficial reactions. The existence of prominent concentration of oxygen vacancy in the nanometric dimension of ceria leading to greater Ce3+ generation by exposed active phase CeO2 nanoparticles is key to achieve a durable hybrid Nafion membrane.

Looking Inside Polymer Electrolyte Membrane Fuel Cell Stack Using Tailored Electrochemical Methods

2020 ◽  
Vol 17 (3) ◽  
Author(s):  
Piotr Piela ◽  
Jens Mitzel ◽  
Sébastien Rosini ◽  
Wojciech Tokarz ◽  
Francesco Valle ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Electrochemical Impedance ◽  
Polymer Electrolyte Membrane ◽  
Hydrogen Permeability ◽  
Active Surface ◽  
Electrochemical Methods ◽  
Membrane Electrode ◽  
Electrolyte Membrane ◽  
Surface Areas

Abstract Voltammetry, potentiometry, amperometry, and electrochemical impedance spectroscopy (EIS) were used to study practical polymer electrolyte membrane fuel cell (PEMFC) stacks in an attempt to validate the stack-tailored electrochemical methods and to show the range of information about a PEMFC stack obtainable with the methods. In-stack electrode voltammetry allowed to determine the type, i.e., the surface chemistry, of catalysts used to make the stack electrodes and to measure the electrodes’ true active surface areas (EASAs). Stack potentiometry gave the EASAs, too, but only after calibration of the method against voltammetry. The speed of the test is the advantage of the stack potentiometry. An amperometry-based protocol was introduced to measure the hydrogen permeability and electronic shorting of the stack membrane-electrode assemblies. Dependence of the H2 permeability on H2 pressure and the stack temperature was shown. EIS in the hydrogen-pump mode was used to study the anode and electrolyte membrane processes under load. Spectra were dominated by humidification effects, which allowed probing the external humidification distribution to the anodes in the stack. Cathode EIS spectra obtained by subtraction of H2-H2-mode spectra from H2-air-mode spectra were modeled and the ohmic, charge-transfer, and oxygen mass-transport contributions to the stack polarization under load were separated. The variability of these contributions across the stack was discussed.

Prism-patterned Nafion membrane for enhanced water transport in polymer electrolyte membrane fuel cell

2016 ◽  
Vol 317 ◽  
pp. 19-24 ◽  
Author(s):  
Sang Moon Kim ◽  
Yun Sik Kang ◽  
Chiyeong Ahn ◽  
Segeun Jang ◽  
Minhyoung Kim ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Water Transport ◽  
Polymer Electrolyte Membrane ◽  
Nafion Membrane ◽  
Electrolyte Membrane

scholarly journals Numerical Simulation on Impacts of Thickness of Nafion Series Membranes and Relative Humidity on PEMFC Operated at 363 K and 373 K

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8256
Author(s):  
Akira Nishimura ◽  
Kyohei Toyoda ◽  
Yuya Kojima ◽  
Syogo Ito ◽  
Eric Hu
Keyword(s):  
Numerical Simulation ◽  
Relative Humidity ◽  
Polymer Electrolyte ◽  
Current Density ◽  
Polymer Electrolyte Membrane ◽  
Catalyst Layer ◽  
Nafion Membrane ◽  
Membrane Thickness ◽  
Electrolyte Membrane ◽  
The Impact

The purpose of this study is to understand the impact of the thickness of Nafion membrane, which is a typical polymer electrolyte membrane (PEM) in Polymer Electrolyte Membrane Fuel Cells (PEMFCs), and relative humidity of supply gas on the distributions of H2, O2, H2O concentration and current density on the interface between a Nafion membrane and anode catalyst layer or the interface between a Nafion membrane and cathode catalyst layer. The effect of the initial temperature of the cell (Tini) is also investigated by the numerical simulation using the 3D model by COMSOL Multiphysics. As a result, the current density decreases along with the gas flow through the gas channel irrespective of the Nafion membrane thickness and Tini, which can be explained by the concentration distribution of H2 and O2 consumed by electrochemical reaction. The molar concentration of H2O decreases when the thickness of Nafion membrane increases, irrespective of Tini and the relative humidity of the supply gas. The current density increases with the increase in relative humidity of the supply gas, irrespective of the Nafion membrane thickness and Tini. This study recommends that a thinner Nafion membrane with well-humidified supply gas would promote high power generation at the target temperature of 363 K and 373 K.

scholarly journals Lifetime Prediction of a Polymer Electrolyte Membrane Fuel Cell under Automotive Load Cycling Using a Physically-Based Catalyst Degradation Model

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2054 ◽  
Author(s):  
Manik Mayur ◽  
Mathias Gerard ◽  
Pascal Schott ◽  
Wolfgang Bessler
Keyword(s):  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Polymer Electrolyte Membrane ◽  
Catalyst Layer ◽  
Active Surface ◽  
Temporal Variations ◽  
Multiscale Simulation ◽  
Active Surface Area ◽  
State Variables ◽  
Electrolyte Membrane

One of the bottlenecks hindering the usage of polymer electrolyte membrane fuel cell technology in automotive applications is the highly load-sensitive degradation of the cell components. The cell failure cases reported in the literature show localized cell component degradation, mainly caused by flow-field dependent non-uniform distribution of reactants. The existing methodologies for diagnostics of localized cell failure are either invasive or require sophisticated and expensive apparatus. In this study, with the help of a multiscale simulation framework, a single polymer electrolyte membrane fuel cell (PEMFC) model is exposed to a standardized drive cycle provided by a system model of a fuel cell car. A 2D multiphysics model of the PEMFC is used to investigate catalyst degradation due to spatio-temporal variations in the fuel cell state variables under the highly transient load cycles. A three-step (extraction, oxidation, and dissolution) model of platinum loss in the cathode catalyst layer is used to investigate the cell performance degradation due to the consequent reduction in the electro-chemical active surface area (ECSA). By using a time-upscaling methodology, we present a comparative prediction of cell end-of-life (EOL) under different driving behavior of New European Driving Cycle (NEDC) and Worldwide Harmonized Light Vehicles Test Cycle (WLTC).

Effect of gas composition on Ru dissolution and crossover in polymer-electrolyte membrane fuel cells

2010 ◽  
Vol 195 (15) ◽  
pp. 4622-4627 ◽  
Author(s):  
Tommy T.H. Cheng ◽  
Nengyou Jia ◽  
Vesna Colbow ◽  
Silvia Wessel ◽  
Monica Dutta
Keyword(s):  
Fuel Cells ◽  
Polymer Electrolyte ◽  
Polymer Electrolyte Membrane ◽  
Gas Composition ◽  
Electrolyte Membrane
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