Teixeira, Fatimade Sá, A.I.Teixeira, António P. S.Rangel, C. M.2020-03-242020-03-242019Teixeira, Fátima C... [et.al.] - Enhanced proton conductivity of Nafion-azolebisphosphonate membranes for PEM fuel cells. In: New Journal of Chemistry, 2019, Vol. 43, p. 15249-152571144-0546http://hdl.handle.net/10400.9/3199ABSTRACT: 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.engFuel cellsPolymer electrolyte membranePEMProton exchange membranejournal article10.1039/c9nj03405f