Understanding of free radical scavengers used in highly durable proton exchange membranes

• Published in: Progress in natural science Vol. 30; no. 6; pp. 732 - 742
• Main Authors: Rui, Zhiyan, Liu, Jianguo
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2020
• Subjects: Chemical degradation; Free radical scavenger; Fuel cell; Lifetime; Proton exchange membrane; Free radical scavenger; Lifetime; Chemical degradation; Proton exchange membrane; Fuel cell
• ISSN: 1002-0071
• DOI: 10.1016/j.pnsc.2020.08.013

Lifetime is always one of the core concerns of proton exchange membrane fuel cell, especially in commercial utilization. Membrane failure caused by chemical degradation can lead to crash of the whole fuel cell system. Proton exchange membranes with enhanced chemical durability can be fabricated via the addition of free radical scavengers. Free radical scavengers are a series of compounds that can react with harmful radicals preferentially than ionomers, with the membranes protected. This review presents the free radical scavengers that had been applied to proton exchange membranes. The mechanisms of the additives in scavenging radicals are discussed in detail. Meanwhile, the challenges and drawbacks of free radical scavengers need to be addressed are also highlight. [Display omitted] •Free radical scavengers are effective additives in proton exchange membranes to mitigate chemical degradation.•Mechanisms of chemical degradation of proton exchange membrane at four attack sites are summarized.•The radical scavenging efficacy and regeneration reaction are two bases of free radical scavengers.