Design of Pore Structure in Gas Diffusion Layers for Oxygen Depolarized Cathode and Their Effect on Activity for Oxygen Reduction Reaction

2014 ◽  
Vol 53 (14) ◽  
pp. 5866-5872 ◽  
Author(s):  
Jingjun Liu ◽  
Chao Yang ◽  
Chenguang Liu ◽  
Feng Wang ◽  
Ye Song

1991 ◽  
Vol 23 (3) ◽  
pp. 247-252 ◽  
Author(s):  
Masakazu Sakaguchi ◽  
Mineo Sato ◽  
Miki Kawashima ◽  
Yoshikazu Sato


2022 ◽  
Vol 334 ◽  
pp. 04012
Author(s):  
Giulia Massaglia ◽  
Eve Verpoorten ◽  
Candido F. Pirri ◽  
Marzia Quaglio

The aim of this work is the development of new nanostructured-gas-diffusion-layer (GDL) to improve the overall behaviour of Air-Cathode Single-Chamber-Microbial-Fuel-Cells (SCMFCs). The design of new nanostructured-GDL allowed exploiting all nanofibers ’intrinsic properties, such as high surface ratio to volume, high porosity, achieving thus a good oxygen diffusion into the proximity of catalyst layer, favouring thus the direct oxygen-reduction-reaction (ORR). Nanostructured-GDLs were prepared by electrospinning process, using a layer-by-layer deposition to collect 2 nanofibers’ mats. The first layer was made of cellulose nanofibers able to promote oxygen diffusion into SCMFC. The second layer, placed outwards, was based on polyvinyl-fluoride (PVDF) nanofibers to prevent the electrolyte leakage. This nanostructured-GDL plays a pivotal role to improve the overall performance of Air-Cathode-SCMFCs. A maximum current density of 20 mA m-2 was obtained, which is higher than the one reached with commercial-GDL, used as reference material. All results were analysed in terms of energy recovery parameter, defined as ratio of generated power integral and the internal volume of devices, evaluating the overall SCMFC performance. SCMFCs with a nanostructured-GDL showed an energy recovery equal to 60.83 mJ m-3, which was one order of magnitude higher than the one obtained with commercial-GDL, close to 3.92 mJ m-3.





2021 ◽  
Author(s):  
Yu-Ping Ku ◽  
Konrad Ehelebe ◽  
Markus Bierling ◽  
Florian Speck ◽  
Dominik Seeberger ◽  
...  

Abstract The electrochemical activity of modern Fe-N-C electrocatalysts in alkaline media is on par with that of platinum. For successful application in fuel cells, however, also high durability and longevity must be demonstrated. Currently, design and synthesis of simultaneously active and stable platinum group metal-free electrocatalysts is hindered by a limited understanding of Fe-N-C degradation, especially under operando conditions. In this work, using a gas diffusion electrode half-cell coupled with inductively coupled plasma mass spectrometry setup, Fe dissolution is studied under more realistic conditions, i.e. real catalyst layer and current densities up to 125 mA·cm-2. Varying the rate of oxygen reduction reaction, we show a remarkable correlation between Faradaic electrode charge and Fe dissolution. This finding is rationalized assuming that oxygen reduction and Fe dissolution reactions are interlinked, likely through a common intermediate formed during the Fe3+/Fe2+ redox transitions in coordinated Fe cations. Moreover, such linear correlation allows an introduction and use of a simple metric (stability number). Hence, in the current work, a powerful tool for a more applied stability screening of different electrocatalysts is introduced, which allows on the one hand fast performance investigations under more realistic conditions, and on the other hand more advanced mechanistic understanding of Fe-N-C degradation in catalyst layers.





RSC Advances ◽  
2015 ◽  
Vol 5 (87) ◽  
pp. 70743-70748 ◽  
Author(s):  
Zhiwei Liu ◽  
Ping Li ◽  
Fuqiang Zhai ◽  
Qi Wan ◽  
Alex A. Volinsky ◽  
...  

Nanostructured tungsten carbide is used as the catalyst in a gas diffusion electrode. The presence of the appropriate amorphous carbon is beneficial for improving the conductivity and dispersibility of the tungsten carbide catalyst.



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