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

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.

scholarly journals 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

2021 ◽  
Author(s):  
Marco Renzi ◽  
Francesco Nobili ◽  
Krzysztof Miecznikowski ◽  
Aldona Kostuch ◽  
Anna Wadas ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Relative Humidity ◽  
Stress Test ◽  
Membrane Electrode Assembly ◽  
Reduction Reaction ◽  
Composite Catalyst ◽  
Membrane Electrode ◽  
Cell Potential ◽  
Zeolite Type ◽  
Low Pt Loading

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.

scholarly journals Boosting efficiency and stability using zirconia nanosphere-held carbon for proton exchange membrane fuel cells

RSC Advances ◽  
2018 ◽  
Vol 8 (1) ◽  
pp. 472-480 ◽  
Author(s):  
P. Dhanasekaran ◽  
Sharon R. Williams ◽  
D. Kalpana ◽  
Santoshkumar D. Bhat
Keyword(s):  
Fuel Cells ◽  
Proton Exchange Membrane ◽  
Stress Test ◽  
Pt Nanoparticles ◽  
Proton Exchange ◽  
Carbon Corrosion ◽  
Accelerated Stress Test ◽  
Exchange Membrane

Corrosion during the accelerated stress test for Pt on carbon and Pt on Zr–C 3 composite representing the steps for reduced carbon corrosion, stabilized Pt nanoparticles and re-deposition of Pt nanoparticles on the ZrO2:C composite.

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

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.

scholarly journals Intermetallic Platinum Alloy Nanoparticles and Single Atoms Hybrid Electrocatalysts for Proton Exchange Membrane Fuel Cells

2021 ◽  
Author(s):  
Minhua Shao ◽  
Fei Xiao ◽  
Qi Wang ◽  
Gui-Liang Xu ◽  
Xueping Qin ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Active Sites ◽  
Proton Exchange Membrane ◽  
Synergistic Effects ◽  
Reduction Reaction ◽  
Proton Exchange ◽  
Alloy Nanoparticles ◽  
Single Atoms ◽  
Low Pt Loading ◽  
Exchange Membrane

Abstract Proton exchange membrane fuel cell converts hydrogen and oxygen into electricity with zero emission1. The high cost and low durability of Pt-based electrocatalysts for oxygen reduction reaction hinder its wide applications2,3. The development of non-precious metal electrocatalysts also reaches the bottleneck because of the low activity and durability4,5. Here we rationally design a hybrid electrocatalyst consisting of atomically dispersed Pt and Fe single atoms and intermetallic PtFe alloy nanoparticles. The Pt mass activity of the hybrid catalyst is 3.5 times higher than that of commercial Pt/C in a fuel cell. More importantly, the fuel cell with an ultra-low Pt loading in the cathode (0.015 mgPt cm-2) shows unprecedented durability, with 93.6% activity retention after 100,000 cycles and no noticeable current drop at 0.6 V for at least 206 h. These results highlight the importance of the synergistic effects among active sites in hybrid electrocatalysts and provide an alternative way to design more active and durable low-Pt electrocatalysts for electrochemical devices.

Sign in / Sign up

Export Citation Format

Share Document