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

• Autor(a) principal: Teixeira, Fatima
• Data de Publicação: 2019
• Outros Autores: de Sá, A.I., Teixeira, António P. S., Rangel, C. M.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.9/3199
• topic: Fuel cells; Polymer electrolyte membrane; PEM; Proton exchange membrane

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.