Vicious cycle during chemical degradation of sulfonated aromatic proton exchange membranes in the fuel cell application

Karimi, Azam; Mirfarsi, Seyed Hesam; Rowshanzamir, Soosan; Beyraghi, Fatemeh; Lester, Daniel W.

doi:10.1002/er.5596

Cited by 9 publications

(4 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…PEMs suffer mechanical stresses induced by RH fluctuation, temperature mismanagement, and poor fabrication of MEA 13,21 . Secondly, the inevitable generation of reactive radicals within the membrane during PEFC operation and their intrinsic propensity for hydrogen abstraction result in chemical degradation of PEMs which manifests itself as defect and pinhole formation 22,23 . Although the hydroxyl ( ˙ OH) and hydroperoxyl ( ˙ OOH) destructive intermediates can be formed directly within the PEM, the most likely path for radical formation is reportedly the hydrogen peroxide (H 2 O 2 ) decomposition while metal transition ions, for example, Fe 2+ , are present 24 …”

Section: Introductionmentioning

confidence: 99%

“…13,21 Secondly, the inevitable generation of reactive radicals within the membrane during PEFC operation and their intrinsic propensity for hydrogen abstraction result in chemical degradation of PEMs which manifests itself as defect and pinhole formation. 22,23 Although the hydroxyl (˙OH) and hydroperoxyl (˙OOH) destructive intermediates can be formed directly within the PEM, the most likely path for radical formation is reportedly the hydrogen peroxide (H 2 O 2 ) decomposition while metal transition ions, for example, Fe 2+ , are present. 24 Along with the above-mentioned radicals, other intermediates such as ˙H have been detected in an in situ fuel cell test working with Nafion and SPEEK membranes by the spin-trapping electron spin resonance (ESR) technique.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Numerical investigation of gas cross‐over and hydrogen peroxide formation in hydrocarbon‐based fuel cell membranes

Karimi

Kalfati

Mirfarsi

et al. 2022

Intl J of Energy Research

Self Cite

View full text Add to dashboard Cite

Summary Although hydrocarbon‐based proton exchange membranes have gained popularity, their durability needs further evaluation. In this study, a dynamic model is developed for a membrane electrode assembly (MEA) working with sulfonated poly (ether ether ketone) (SPEEK) membrane to predict the concentration profiles of reactants inside the MEA, their cross‐over in the membrane, and hydrogen peroxide formation via chemical and electrochemical modes as a function of voltage and membrane thickness. Results show that reactants cross‐over, especially oxygen is accelerated under high voltages, promoting the chemical mode of H2O2 formation, whereas the voltage driving force and oxygen concentration simultaneously control the electrochemical mode. Moreover, a 50% reduction in SPEEK membrane thickness yields about 90%, 200%, and up to 50% rise in reactant cross‐over, chemical, and electrochemical H2O2 formation modes, respectively. The figures for the chemical mode of H2O2 formation are five orders of magnitude greater than their electrochemical counterparts. This numerical study shows that the most attention should be paid to the anode/membrane interface to mitigate the chemical degradation of hydrocarbon‐based proton exchange membranes.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Numerical investigation of gas cross‐over and hydrogen peroxide formation in hydrocarbon‐based fuel cell membranes

Karimi

Kalfati

Mirfarsi

et al. 2022

Intl J of Energy Research

Self Cite

View full text Add to dashboard Cite

show abstract

“…The proton conductivity comes from SPEEK, while the hydrophobic polymer provides mechanical integrity. [19][20][21] Another important issue with block copolymers is their low proton conductivity when PEMFCs are operated at low RH. Efforts to overcome this limitation have included blending with hygroscopic materials, functionalized carbon nanomaterials, phosphotungstic acid, or functionalized metal sulfide.…”

Section: Introductionmentioning

confidence: 99%

Enhanced performance and durability of composite membranes containing anatase titanium oxide for fuel cells operating under low relative humidity

Kim

Vinothkannan

Lee

et al. 2021

Intl J of Energy Research

View full text Add to dashboard Cite

In this work, sulfonated diblock copolymers (SDBCs) were prepared by polycondensation of sulfonated poly(ether-ether-ketone) (SPEEK) and hydrophobic oligomer, which were combined with sintered anatase titanium oxide (S-An-TiO 2 ) to create a hybrid membrane for apply in proton exchange membrane fuel cells (PEMFCs) operating with low relative humidity (RH). Then, a series of composite membranes (SDBC/S-An-TiO 2 ) were prepared by varying the wt% of S-An-TiO 2 blended with SDBC. The results showed that appropriate quantity (ie, 15 wt%) of S-An-TiO 2 can significantly improve the proton conductivity and physiochemical properties of prepared composite membrane, as well as the PEMFC performance and durability under 20% RH. The 1.5 wt% of SDBC/ S-An-TiO 2 offers high current output, power output, and durability values at 60 C under 20% RH, which are 0.207 A cm À2 , 0.074 W cm À2 and over 90 hours, respectively. These results can be attributed to the good interfacial compatibility between S-An-TiO 2 and SDBC.

show abstract

“…In addition, in terms of stability, these membranes undergo chemical degradation as well as mechanical stresses during fuel cell operation. Free radicals' attack to the polymeric structure of membranes leads to chemical degradation and the formation of pinholes [14][15][16]. These radicals are generated by the cross-over of hydrogen to the cathode side, oxygen to the anode side, and also an incomplete oxygen reduction reaction.…”

Section: Introductionmentioning

confidence: 99%

Self-Humidifying Proton Exchange Membranes for Fuel Cell Applications: Advances and Challenges

2020

Self Cite

View full text Add to dashboard Cite

Polymer electrolyte fuel cells (PEFCs) provide efficient and carbon-free power by converting the hydrogen chemical energy. The PEFCs can reach their greatest performance in humidified condition, as proton exchange membranes (PEMs) should be humidified for their proton transportation function. Thus, external humidifiers are commonly employed to increase the water content of reactants. However, being burdened with external humidifiers can make the control of PEFCs complicated and costly, in particular for transportation application. To overcome this issue, self-humidifying PEMs have been introduced, with which PEFC can be fed by dry reactants. In fact, internal humidification is accomplished by produced water from the recombination of permeated hydrogen and oxygen gases on the incorporated platinum catalysts within the PEM. While the water production agent remains constant, there is a broad range of additives that are utilized to retain the generated water and facilitate the proton conduction path in the PEM. This review paper has classified the aforementioned additives in three categories: inorganic materials, proton-conductive materials, and carbon-based additives. Moreover, synthesis methods, preparation procedures, and characterization tests are overviewed. Eventually, self-humidifying PEMs endowed with platinum and different additives are compared from performance and stability perspectives, such as water uptake, proton conductivity, fuel cell performance, gas cross-over, and the overall durability. In addition, their challenges and possible solutions are reviewed. Considering the concerns regarding the long-term durability of such PEMs, it seems that further investigations can be beneficial to confirm their reliability for prolonged PEFC operation.

show abstract

Vicious cycle during chemical degradation of sulfonated aromatic proton exchange membranes in the fuel cell application

Cited by 9 publications

References 56 publications

Numerical investigation of gas cross‐over and hydrogen peroxide formation in hydrocarbon‐based fuel cell membranes

Numerical investigation of gas cross‐over and hydrogen peroxide formation in hydrocarbon‐based fuel cell membranes

Enhanced performance and durability of composite membranes containing anatase titanium oxide for fuel cells operating under low relative humidity

Self-Humidifying Proton Exchange Membranes for Fuel Cell Applications: Advances and Challenges

Contact Info

Product

Resources

About