Stabilization of Perfluorinated Membranes Using Ce
            <sup>3+</sup>
            and Mn
            <sup>2+</sup>
            Redox Scavengers

Coms, Frank D.; Schlick, Shulamith; Danilczuk, Marek

doi:10.1002/9781119196082.ch4

Cited by 13 publications

(11 citation statements)

References 42 publications

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“…Furthermore, additives incorporated into the membrane merely by doping may move and be leached out over time. 17 Tethering of the functional motifs to the polymer chain or an inorganic filler may be a promising approach for immobilization.…”

Section: Future Needs and Prospectsmentioning

confidence: 99%

Perspective—Prospects for Durable Hydrocarbon-Based Fuel Cell Membranes

Gubler

Nauser

Coms

et al. 2018

J. Electrochem. Soc.

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Various types of hydrocarbon-based ionomer membranes have been proposed for application in fuel cells as an alternative to perfluoroalkylsulfonic acid (PFSA) membranes. The issue of chemical and mechanical degradation of this class of ionomer membranes and the combination thereof, especially under automotive operating conditions, has not been fully resolved at present. Here, we highlight key degradation mechanisms of hydrocarbon-based membranes in the fuel cell and identify necessary developments to mitigate radical induced membrane degradation and mechanical shortcomings of this class of ionomers that may enable them to compete with and, possibly, replace PFSA membranes.

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Section: Future Needs and Prospectsmentioning

confidence: 99%

Perspective—Prospects for Durable Hydrocarbon-Based Fuel Cell Membranes

Gubler

Nauser

Coms

et al. 2018

J. Electrochem. Soc.

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“…We assume that the attack of the polymer P by HO • leads to the formation of intermediates P*, which then undergo further reactions. We describe the degradation by a "lumped" effective first-order rate constant k eff , which embodies a combination of different reactions, as indicated in Scheme 2 and reaction (8).…”

Section: Methods-kinetics Modelmentioning

confidence: 99%

Possible Repair Mechanism for Hydrocarbon-Based Ionomers Following Damage by Radical Attack

Wild

Németh

Nolte

et al. 2021

J. Electrochem. Soc.

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Polymer electrolyte fuel cell (PEFC) membranes are subject to radical-induced degradation. Antioxidant strategies for hydrocarbon-based ionomers containing aromatic units can focus on intermediates that are formed upon attack by hydroxyl radicals (HO • ). Among the different intermediates, the cation radical P •+ is the most promising target for repair, for example by cerium(III). For the "repair" reaction of Ce(III) with radicals of a poly(α-methylstyrene sulfonate) oligomer we determined an activation energy of (9 ± 2) kJ mol −1 and a rate constant of 1.6 • 10 8 M −1 s −1 at 80°C by pulse-radiolysis. For the reduction of Ce(IV) by hydrogen peroxide the activation energy was determined by stopped-flow as (30 ± 1) kJ mol −1 with a rate constant of 4.8 • 10 6 M −1 s −1 at 80°C. These parameters are fed into a kinetics model to estimate the efficacy of the cerium (III)/(IV) redox couple as a catalytic repair agent in hydrocarbon-based fuel cell membranes. While cerium can mitigate polymer degradation, repair efficacy depends on the polymer degradation pathway and the nature and lifetime of the intermediates.

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“…6,7 In order to improve the chemical durability of PFSA membranes, a countermeasure introducing antioxidant additives (e.g., organic species, inorganic nanoparticles, and metal ions) into membranes was established. 9−15 In particular, doping inorganic nanoparticles or metal ions, such as CeO 2 , 11,16,17 Ce 3+ , 12,21 and Mn 2+ , 12,21 into PFSA ionomers is a widely accepted approach due to their facilitation and effectiveness. It has been confirmed that the decomposition rate of H 2 O 2 increases in the order of SiO 2 < Al 2 O 3 < TiO 2 < CeO 2 < ZrO 2 .…”

Section: Introductionmentioning

confidence: 99%

Reinforced Composite Membranes Based on Expanded Polytetrafluoroethylene Skeletons Modified by a Surface Sol–Gel Process for Fuel Cell Applications

Liu

Qiao

et al. 2021

Energy Fuels

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Intercalating expanded polytetrafluoroethylene (ePTFE) reinforcements and incorporating antioxidants (e.g., CeO2 and ZrO2) into perfluorosulfonic acid (PFSA) ionomers are typical methods used to improve the physical and chemical durability of PFSA-based proton exchange membranes, respectively. Nevertheless, these two popular methods still suffer from respective inherent limitations, including the poor interfacial binding between hydrophobic ePTFE and polar PFSA ionomers and the migration and loss of incorporated antioxidants. To solve these two issues simultaneously, we propose a solution based on a surface sol–gel process, by which the deposition of ZrO2 coating on polydopamine-modified ePTFE skeletons not only improves the interfacial bonding of the skeletons and PFSA ionomer but also restrains the migration and loss of antioxidant additives. The results show that the ZrO2-deposited ePTFE exhibits improved hydrophilicity and the reinforced composite membranes based on the modified ePTFE skeletons with one layer of ZrO2 coating are endowed with superior proton conductivity, mechanical properties, dimensional stability, and open-circuit voltage durability. In addition, the stability of the ZrO2 coating on the ePTFE skeletons is also verified.

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Stabilization of Perfluorinated Membranes Using Ce ³⁺ and Mn ²⁺ Redox Scavengers

Cited by 13 publications

References 42 publications

Perspective—Prospects for Durable Hydrocarbon-Based Fuel Cell Membranes

Perspective—Prospects for Durable Hydrocarbon-Based Fuel Cell Membranes

Possible Repair Mechanism for Hydrocarbon-Based Ionomers Following Damage by Radical Attack

Reinforced Composite Membranes Based on Expanded Polytetrafluoroethylene Skeletons Modified by a Surface Sol–Gel Process for Fuel Cell Applications

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Stabilization of Perfluorinated Membranes Using Ce 3+ and Mn 2+ Redox Scavengers

Cited by 13 publications

References 42 publications

Perspective—Prospects for Durable Hydrocarbon-Based Fuel Cell Membranes

Perspective—Prospects for Durable Hydrocarbon-Based Fuel Cell Membranes

Possible Repair Mechanism for Hydrocarbon-Based Ionomers Following Damage by Radical Attack

Reinforced Composite Membranes Based on Expanded Polytetrafluoroethylene Skeletons Modified by a Surface Sol–Gel Process for Fuel Cell Applications

Contact Info

Product

Resources

About

Stabilization of Perfluorinated Membranes Using Ce ³⁺ and Mn ²⁺ Redox Scavengers