Study on fiber-reinforced proton exchange membrane using high-surface-energy substrate

2021 ◽  
pp. 119940
Author(s):  
Min Wang ◽  
Wenjia Ma ◽  
Congrong Yang ◽  
Zhangxun Xia ◽  
Suli Wang ◽  
...  
2021 ◽  
Vol 308 ◽  
pp. 01019
Author(s):  
Haoran Kong ◽  
Jiarong Liu ◽  
Yu Yue

The selection of oxygen reduction reaction (ORR) catalysts plays a key role in enhancing the performance of proton exchange membrane fuel cells (PEMFCs). To optimize the energy conversion technology in PEMFCs and improve the cost-effectiveness of ORR catalysts, atomically dispersed metal-nitrogen-carbon (M-N-C) catalyst is regarded as one of the most promising materials to replace Pt-based catalysts. In this review, we summarize the advantages of atomically dispersed M-N-C catalysts in both physical and chemical properties, including controllable dimensions, ease of accessibility, high surface area and excellent conductivity. Additionally, the unique merits of their cost-effectiveness are also described by a concise comparison with other ORR catalysts. Subsequently, some of its main synthesis methods are based on the most commonly used zeolitic imidazolate framework (ZIF) precursor. Several other precursors involve carbon, nitrogen, and one or more active transition metals (mainly iron or cobalt) are introduced briefly. Although there are a variety of synthesis methods, all these methods are in line with pyrolysis technology. Then, the recent advancements of atomically dispersed M-N-C catalysts related to their development and application of Fe-N-C, Mn-N-C, and Co-N-C catalysts are comprehensively described. Finally, based on some common M-N-C catalysts, many improvement ideas are also proposed. The focus is on how to control the negative reaction in Fe-N-C catalysts, improve the activity of Co-N-C catalysts and Mn-N-C catalysts, and find more suitable transition metal materials to prepare M-N-C catalysts.


2012 ◽  
Vol 15 (3) ◽  
pp. 165-170 ◽  
Author(s):  
M.L. Hernández-Pichardo ◽  
R.G. González-Huerta ◽  
P. Del Angel ◽  
E. Palacios-González ◽  
S.P. Paredes-Carrera

Platinum nanoparticles supported on high surface area carbon black (e.g., Vulcan XC-72) are the most commonly used catalysts for both cathode and anode in proton exchange membrane fuel cells (PEMFCs), however, some other catalysts such as Pt/MoOx and Pt/WOx are also considered promising, due to their higher activity, stability and enhanced CO tolerance. This work is focused on the synthesis and characterization of nanostructured Pt/WOx-C as both cathode and anode electrocatalysts for PEMFCs. The Pt deposit on the surface of the support is a crucial step in the synthesis of the catalytic materials. Because of this, different synthesis methods were probed in order to find the conditions for the higher dispersion and accessibility of Platinum over the WOx-C support and to improve the PEMFC cathode stability. The catalysts were prepared by UV and ultrasound assisted approaches, and characterized by Transmission Electron Microscopy as well as lineal and cyclic voltammetry.


Author(s):  
Vinay K. Adigoppula ◽  
Waseem Khan ◽  
Rajib Anwar ◽  
Avni A. Argun ◽  
R. Asmatulu

Nanocomposite proton-exchange membranes are fabricated by loading graphene nanoflakes into perfluoro sulfonic acid polymer (Nafion) solutions at controlled amounts (1–4 wt%) followed by electrical and thermal characterization of the resulting membranes. Electronic and ionic conductivity values of the nanocomposites, as well as their dielectric and thermal properties improve at increased graphene loadings. Owing to graphene’s exceptionally high surface area to volume ratio and excellent physical properties, these nanocomposite are promising candidates for proton-exchange membrane fuel cell applications.


2021 ◽  
Vol 13 ◽  
Author(s):  
Hamid Ilbeygi

Background: Proton exchange membrane is art of PEM fuel cells, developing active materials with robust structure and high proton conductivity has attained huge attention in recent decade amongst researchers. Aims/objectives: Here we have developed a novel approach to prepare a siliceous mesoporous heteropoly acid with high stability in polar media and high proton conductivity to be utilized as proton exchange membrane. Methods: A highly stable mesoporous siliceous phosphomolybdic acid has been synthesized via a simple self-assembly between phosphomolybdic acid (PMA), the polymeric surfactant, and the silica precursor stabilized by KCl molecules as a proton conducting material for proton exchange membrane application. Results: As prepared siliceous mesoporous phosphomolybdic acids (mPMA-Si) show a high surface area with a highly crystalline structure, however the crystallinity reduced by increasing the silica content. Further analysis proved the Keggin structure remain intact in final materials. mPMA-8 Si shows the highest performance among all the materials studied with proton conductivity of 0.263 S.cm-1 at 70 oC. Conclusion: As prepared mPMA-xSi has shown a very high proton conductivity in a range of temperatures which make them a promising material for proton exchange membrane.


Author(s):  
Elaine Petrach ◽  
Ismat Abu-Isa ◽  
Xia Wang

The bipolar plate is an important and integral part of the proton exchange membrane (PEM) fuel cell and PEM fuel cell stacks. Currently bipolar plates represent more than 80% by weight and 40% by cost of the fuel cell stack. Traditional materials used for bipolar plates are primarily graphite and metal. Search for alternative materials to improve weight and cost considerations is needed. This paper discusses the results of an investigation of two elastomeric materials being developed for bipolar plate applications. Perceived advantages of the use of elastomers for this application include improved sealability without additional gasket material, reduction in the contact resistance between individual cells, improved formability, and weight reduction. The first elastomer investigated is a two component liquid silicone rubber, and the second is a polyolefin thermoplastic elastomer. These polymer matrix materials are made electrically conductive by the addition of conductive fillers including thermal graphite fibers (Cytec DKD & CKD), high surface area conductive carbon black nanoparticles (Cabot Black Pearls 2000), and graphite flakes (Asbury 4012). Electrical conductivity, processability, and elastic behavior measurements of the composites have been conducted. Some of silicone-graphite fiber composites material exhibit conductivity values comparable to those of the traditional graphite plate materials. Elasticity of all composites is maintained even at high filler concentrations.


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