Contribution of zeolitic imidazolate framework-8 in improving the performance of polymer electrolyte membrane for direct methanol fuel cell

• Main Authors: Junoh, H., Awang, N., Ahmad, S.N.A., Azhar, M., Jaafar, J., Nordin, N.A.H.M., Ismail, A.F., Qtaishat, M.R., Matsuura, T., Othman, M.H.D., Rahman, M.A., Zainoodin, A.M.
• Format: Article
• Published: 2024
• Online Access: http://scholars.utp.edu.my/id/eprint/37729/; https://www.scopus.com/inward/record.uri?eid=2-s2.0-85174345638&doi=10.1016%2fj.jssc.2023.124395&partnerID=40&md5=4350785615c7f827c9c508bdd0fc3357

Introducing ZIF-8 into the PES-cSMM membranes played a pivotal role in the development of proton-conducting pathways and an effective methanol barrier. We employed dry-wet phase inversion techniques to fabricate PES-cSMM, finding that a 3 wt cSMM content yielded optimal results. The resulting PES-cSMM exhibits impressive performance, with a 38 higher selectivity and a 95 greater methanol barrier compared to Nafion® 117. The imidazole-N-H linker in the terminal PES-cSMM/ZIF-8 promotes proton transport through a hydrogen bond chain, while the hydrophobic backbone acts as an effective methanol filter. As a result, PES-cSMM/ZIF-8 boasts a 13-fold higher water uptake than Nafion® 117 and achieves a 99 improvement in methanol sieving performance, a highly promising breakthrough for DMFC systems. Proton conductivity for the PES-cSMM/ZIF-8 immersion membrane reaches 19.5 � 10-3 Scm-1, comparable to Nafion® 117, which is 20.4 � 10-3 Scm-1. The structural flexibility of ZIF-8 within PES-cSMM facilitates efficient proton conduction, while the ZIF-8 cage acts as a robust methanol barrier. Computational analysis revealed covalent bonding within the PES-cSMM system. We characterized the chemical interactions in PES-cSMM/ZIF-8 using topology analysis, specifically the Atom in Molecules/Non-covalent analysis (AIM/NCI) technique. © 2023 Elsevier Inc.