Phenyl‐Free Polynorbornenes for Potential Anion Exchange Ionomers for Fuel Cells and Electrolyzers. Issue 3 (7th December 2022)

• Record Type: Journal Article
• Authors: Leonard, Daniel P.; Lehmann, Michelle; Klein, Jeffrey M.; Matanovic, Ivana; Fujimoto, Cy; Saito, Tomonori; Kim, Yu Seung
• Is Part Of: Advanced energy materials. Volume 13:Issue 3(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-12-07
• Subjects: anion exchange membranes -- fuel cells -- interaction -- ionomers -- norbornene -- water electrolyzers; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.202203488
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: Ionomers in the catalyst layer play a critical role in the performance of fuel cells and electrolyzers. Phenyl adsorption on hydrogen oxidation catalysts and electrochemical oxidation of phenyl moieties on oxygen evolution catalysts are detrimental to the alkaline devices' performance. Here the adsorption energy of phenyl‐containing ionomers is compared to provide the rationale for implementing phenyl‐free ionomers. Density functional theory calculations indicated that the norbornane fragment has minimal adsorption energy on Pt(111) due to the absence of aromatic π electrons. A soluble quaternized polynorbornene ionomer is prepared by vinyl addition polymerization, and it exhibits high performance in both fuel cells and electrolyzers, proving the advantage of the phenyl‐free structure. This study establishes the phenyl adsorption energy‐electrode performance relationship, highlighting the importance of material interactions between the catalysts and ionomers. Abstract : Assessing the phenyl adsorption energy of the ionomer fragment is a powerful tool to predict ionomer performance in anion exchange membrane‐based electrochemical devices. A phenyl‐free polynorbornene copolymer ionomer synthesized by vinyl addition reaction provides the lowest interaction with electrocatalysts in the catalyst layer, allowing high performance in anion‐exchange membrane fuel cells and water electrolyzers.