Enhanced proton conductivity of Nafion-azolebisphosphonate membranes for PEM fuel cells

ABSTRACT: Fuel cells are among the cleaner alternatives of sustainable energy technologies, where their proton exchange membranes continue to be a key component with many challenges and opportunities ahead. In this study, different indazole- and benzotriazolebisphosphonic acids were prepared and inc...

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Bibliographic Details
Main Author: Teixeira, Fatima (author)
Other Authors: de Sá, A.I. (author), Teixeira, António P. S. (author), Rangel, C. M. (author)
Format: article
Language:eng
Published: 2020
Subjects:
Online Access:http://hdl.handle.net/10400.9/3199
Country:Portugal
Oai:oai:repositorio.lneg.pt:10400.9/3199
Description
Summary:ABSTRACT: Fuel cells are among the cleaner alternatives of sustainable energy technologies, where their proton exchange membranes continue to be a key component with many challenges and opportunities ahead. In this study, different indazole- and benzotriazolebisphosphonic acids were prepared and incorporated into new Nafion-doped membranes up to a 5 wt% loading. The new membranes were characterised, and their proton conductivities were evaluated using electrochemical impedance spectroscopy. Membranes with a 1 wt% loading showed better proton conductivities than Nafion N-115 at all temperature and under relative humidity conditions studied. In these conditions, the best value was observed for the membrane doped with [hydroxy(1H-indazol-3-yl)methanediyl]bis(phosphonic acid) (BP2), with a proton conductivity of 98 mS cm(-1). Activation energy (E-a) values suggests that both Grotthuss and vehicular mechanisms are involved in the proton conduction across the membrane.