Effect of LDH platelets on the transport properties and carbonation of anion exchange membranes. (20th January 2022)

• Record Type: Journal Article
• Authors: Simari, Cataldo; Lufrano, Ernestino; Rehman, Muhammad Habib Ur; Zhegur-Khais, Avital; Haj-Bsoul, Saja; Dekel, Dario R.; Nicotera, Isabella
• Is Part Of: Electrochimica acta. Volume 403(2022)
• Publication Date: 2022-01-20
• Subjects: Anion exchange membrane -- Quaternized polysulfone -- LDH -- Diffusion -- Carbonation; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2021.139713
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: We report on an extensive study on nanocomposite Anion Exchange Membranes (AEMs) based on tetramethylammonium Polysulfone ionomer and Layered Double Hydroxide (LDH) as nanofiller. The AEMs were investigated in both OH − and H C O 3 − forms, comparing swelling capacity and transport properties. Ionic conductivity measurements were performed both by Electrochemical Impedance Spectroscopy and Ziv and Dekel's method, while the water and ions mobility by 1 H Pulse Field Gradient (PFG) NMR spectroscopy. One of the most serious problems to be addressed in AEMs fuel cell technology is that of the significant loss of performance when CO2 is present in the reaction oxidant gas (e.g., air) due to the phenomenon of carbonation. In this work, the carbonation kinetics of AEMs and the effect of LDH filler were addressed through 13 C NMR spectroscopy (including diffusometry and relaxometry measurements). The presence of LDH platelets in the AEM significantly reduces the conversion rate of hydroxide groups. The interaction between the polymer chains and the anionic clay lamellae creates a suitable network that benefits the membrane's ionic conductivity, its mechanical properties (DMA tests), and finally reduces the rate of alkaline degradation. Graphical abstract: Image, graphical abstract