One of current trends of the PEM research is the development of new membranes working at high temperature and low humidity. Acid-doped polybenzimidazoles are particularly appealing because of high proton conductivity without humidification and promising fuel cells performances. PBI contains basic functional groups that can easily interact with strong acids, such as H3PO4, H2SO4, allowing proton migration along the anionic chains via a Grotthuss mechanism. In this work phosphoric acid-doped membranes, synthesised from benzimidazole-based monomers with increased basicity and molecular weight, are described and discussed. The influence of the monomer structure on the transport properties and on the physico-chemical interactions between acid and polymer has been investigated by means of impedance spectroscopy and 31P solid-state NMR. Test of methanol crossover and diffusion have been performed to check the membrane suitability for DMFCs.
Quartarone, E., Carollo, A., Mustarelli, P., Magistris, A., Tomasi, C., Garlaschelli, L., et al. (2006). New polybenzimidazole-based membranes for fuel cells. In Materials Research Society Symposium Proceedings. Springer Nature [10.1557/PROC-0972-AA08-03].
New polybenzimidazole-based membranes for fuel cells
Mustarelli P.;
2006
Abstract
One of current trends of the PEM research is the development of new membranes working at high temperature and low humidity. Acid-doped polybenzimidazoles are particularly appealing because of high proton conductivity without humidification and promising fuel cells performances. PBI contains basic functional groups that can easily interact with strong acids, such as H3PO4, H2SO4, allowing proton migration along the anionic chains via a Grotthuss mechanism. In this work phosphoric acid-doped membranes, synthesised from benzimidazole-based monomers with increased basicity and molecular weight, are described and discussed. The influence of the monomer structure on the transport properties and on the physico-chemical interactions between acid and polymer has been investigated by means of impedance spectroscopy and 31P solid-state NMR. Test of methanol crossover and diffusion have been performed to check the membrane suitability for DMFCs.
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