Activation of bimetallic PtFe nanoparticles with zeolite-type cesium salts of vanadium-substituted polyoxometallates toward electroreduction of oxygen at low Pt loadings for fuel cells

AbstractThe catalytic activity of commercial carbon-supported PtFe (PtFe/C) nanoparticles admixed with mesoporous polyoxometalate Cs3H3PMo9V3O40, (POM3-3–9), has been evaluated towards oxygen reduction reaction (ORR) in acid medium. The polyoxometalate cesium salt co-catalyst/co-support has been prepared by titration using the aqueous solution of phosphovanadomolibdic acid. The synthesized material has been characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The results confirm formation of the polyoxometalate salt with the characteristic Keggin-type structure. The composite catalyst has been prepared by mixing the POM3-3–9 sample with the commercial PtFe/C by sonication. The diagnostic rotating ring-disk voltammetric studies are consistent with good performance of the system with low Pt loading during ORR. The fuel cell membrane electrode assembly (MEA) utilizing the PtFe/POM-based cathode has exhibited comparable or better performance (at relative humidity on the level of 100, 62, and 17%), in comparison to the commercial MEA with higher Pt loading at the cathode. Furthermore, based on the cell potential and power density polarization curves, noticeable improvements in the fuel cell behavior have been observed at the low relative humidity (17%). Finally, the accelerated stress test, which uses the potential square wave between 0.4 V and 0.8 V, has been performed to evaluate MEA stability for at least 100 h. It has been demonstrated that, after initial losses, the proposed catalytic system seems to retain stable performance and good morphological rigidity.

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MOF Derived Catalysts for Oxygen Reduction Reaction in Proton Exchange Membrane Fuel Cell

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.778.275 ◽

2018 ◽

Vol 778 ◽

pp. 275-282

Author(s):

Noaman Khan ◽

Saim Saher ◽

Xuan Shi ◽

Muhammad Noman ◽

Mujahid Wasim Durani ◽

...

Keyword(s):

Carbon Nanotubes ◽

Fuel Cell ◽

Proton Exchange Membrane ◽

Membrane Electrode Assembly ◽

Reduction Reaction ◽

Proton Exchange ◽

Membrane Electrode ◽

Nitrogen Doped ◽

Nitrogen Doped Carbon ◽

Exchange Membrane

Highly porous ZIF-67 (Zeolitic imidazole framework) has a conductive crystalline metal organic framework (MOF) structure which was served as a precursor and template for the preparation of nitrogen-doped carbon nanotubes (NCNTs) electrocatalysts. As a first step, the chloroplatinic acid, a platinum (Pt) precursor was infiltrated in ZIF-67 with a precise amount to obtain 0.12 mg.cm-2 Pt loading. Later, the infiltrated structure was calcined at 700°C in Ar:H2 (90:10 vol%) gas mixture. Multi-walled nitrogen-doped carbon nanotubes were grown on the surface of ZIF-67 crystals following thermal activation at 700°C. The resulting PtCo-NCNTs electrocatalysts were deposited on Nafion-212 solid electrolyte membrane by spray technique to study the oxygen reduction reaction (ORR) in the presence of H2/O2 gases in a temperature range of 50-70°C. The present study elucidates the performance of nitrogen-doped carbon nanotubes ORR electrocatalysts derived from ZIF-67 and the effects of membrane electrode assembly (MEA) steaming on the performance of proton exchange membrane fuel cell (PEMFC) employing PtCo-NCNTs as ORR electrocatalysts. We observed that the peak power density at 70°C was 450 mW/cm2 for steamed membrane electrode assembly (MEA) compared to 392 mW/cm2 for an identical MEA without steaming.

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Stability of a Fe-Rich Cathode Catalyst in an Anion Exchange Membrane Fuel Cell

10.21926/cr.2103003 ◽

2021 ◽

Vol 01 (03) ◽

pp. 1-1

Author(s):

Lin Xie ◽

◽

Donald Kirk ◽

Keyword(s):

Fuel Cell ◽

Power Systems ◽

Stress Test ◽

Reduction Reaction ◽

Potential Cycling ◽

Cell Potential ◽

Accelerated Stress Test ◽

Standby Power ◽

The Stability ◽

Exchange Membrane

Fe-rich alloys have been widely studied as catalyst materials for the cathodic oxygen reduction reaction (ORR) in hydrogen fuel cells, and many have shown high activities. The stability of Fe-rich catalysts has also been researched, and some studies have shown promising results using an accelerated stress test (AST), which uses a potential cycling method. However, for commercial fuel cell applications, such as standby power systems, the catalyst has to tolerate a high potential for a long period, which can not be represented by the AST test. In this paper, the cathode stability of a Fe-rich catalyst was studied using a standby cell potential of 0.9V, a potential shown to be challenging for the competing Pt catalysts. After 1500 hrs of testing, significant morphology changes of both the tested cathode and anode were found due to a Fe leaching process. Other alloy materials, including Ni, Cr, and Mn, were also found leached out along with the Fe species from the catalyst framework. The results are a cautionary note for using Fe based catalysts for AEMFC cathodes.

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Catalytic layer-membrane electrode assembly methods for optimum triple phase boundaries and fuel cell performances

Journal of Materials Chemistry A ◽

10.1039/d0ta07470e ◽

2021 ◽

Author(s):

Imen Fouzaï ◽

Solène Gentil ◽

Victor Costa Bassetto ◽

Wanderson Oliveira Silva ◽

Raddaoui Maher ◽

...

Keyword(s):

Fuel Cell ◽

Membrane Electrode Assembly ◽

Emerging Technology ◽

Membrane Electrode ◽

Catalytic Layer ◽

Phase Boundaries ◽

Layer Membrane ◽

Critical Overview

A critical overview of MEA fabrication techniques is given focusing on the formation of triple phase boundaries, known for increasing PEMFC performances. Print-light-synthesis is a new emerging technology to achieve nanostructred MEA.

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Preparation of a self-humidifying membrane electrode assembly for fuel cell and its performance analysis

Science in China Series G ◽

10.1360/02yw0183 ◽

2003 ◽

Vol 46 (5) ◽

pp. 501 ◽

Cited By ~ 4

Author(s):

Cheng WANG

Keyword(s):

Fuel Cell ◽

Performance Analysis ◽

Membrane Electrode Assembly ◽

Membrane Electrode

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Effects of Cracks on the Mass Transfer of Polymer Electrolyte Membrane Fuel Cell with High Performance Membrane Electrode Assembly

Journal of Wuhan University of Technology-Mater Sci Ed ◽

10.1007/s11595-021-2412-z ◽

2021 ◽

Vol 36 (3) ◽

pp. 318-330

Author(s):

Jinrong Shi ◽

Zhigang Zhan ◽

Di Zhang ◽

Yuan Yu ◽

Xiaoxiang Yang ◽

...

Keyword(s):

Mass Transfer ◽

Fuel Cell ◽

Polymer Electrolyte ◽

High Performance ◽

Polymer Electrolyte Membrane ◽

Membrane Electrode Assembly ◽

Membrane Electrode ◽

Electrolyte Membrane

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Degradation study for membrane electrode assembly of anion exchange membrane fuel cell at a single-cell level

Journal of Materials Chemistry A ◽

10.1039/d1ta05801k ◽

2021 ◽

Author(s):

Jonghyun Hyun ◽

Seok-Hwan Yang ◽

Gisu Doo ◽

Sungyu Choi ◽

Dong-Hyun Lee ◽

...

Keyword(s):

Fuel Cell ◽

Single Cell ◽

Anion Exchange ◽

Membrane Electrode Assembly ◽

Anion Exchange Membrane ◽

Membrane Electrode ◽

Single Cell Level ◽

Cell Level ◽

Degradation Study ◽

Exchange Membrane

The durability of the membrane electrode assembly (MEA) is one of the important requirements for the successful commercialization of anion exchange membrane fuel cells (AEMFCs). While chemical stabilities of the...

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Critique and Improvement of a One-Dimensional Semianalytical Model of a Direct Methanol Fuel Cell

Journal of Fuel Cell Science and Technology ◽

10.1115/1.4006842 ◽

2012 ◽

Vol 9 (5) ◽

Cited By ~ 2

Author(s):

C. C. Kuo ◽

W. E. Lear ◽

J. H. Fletcher ◽

O. D. Crisalle

Keyword(s):

Fuel Cell ◽

Polarization Curve ◽

Current Density ◽

Direct Methanol Fuel Cell ◽

Membrane Electrode Assembly ◽

Membrane Electrode ◽

One Dimensional ◽

Implicit Equation ◽

Direct Methanol ◽

Methanol Fuel Cell

A constructive critique and a suite of proposed improvements for a recent one-dimensional semianalytical model of a direct methanol fuel cell are presented for the purpose of improving the predictive ability of the modeling approach. The model produces a polarization curve for a fuel cell system comprised of a single membrane-electrode assembly, based on a semianalytical one-dimensional solution of the steady-state methanol concentration profile across relevant layers of the membrane electrode assembly. The first improvement proposed is a more precise numerical solution method for an implicit equation that describes the overall current density, leading to better convergence properties. A second improvement is a new technique for identifying the maximum achievable current density, an important piece of information necessary to avoid divergence of the implicit-equation solver. Third, a modeling improvement is introduced through the adoption of a linear ion-conductivity model that enhances the ability to better match experimental polarization-curve data at high current densities. Fourth, a systematic method is advanced for extracting anodic and cathodic transfer-coefficient parameters from experimental data via a least-squares regression procedure, eliminating a potentially significant parameter estimation error. Finally, this study determines that the methanol concentration boundary condition imposed on the membrane side of the membrane-cathode interface plays a critical role in the model’s ability to predict the limiting current density. Furthermore, the study argues for the need to carry out additional experimental work to identify more meaningful boundary concentration values realized by the cell.

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