Amino- and Sulfonate-Functionalized Metal–Organic Framework for Fabrication of Proton Exchange Membranes with Improved Proton Conductivity
Rajib Moi, Arijit Ghorai, Susanta Banerjee, Kumar Biradha
Abstract
Metal–organic frameworks (MOFs) are emerging as highly promising candidates for the next-generation proton conductors. Particularly, the amine-containing as well as various acid-functionalized MOFs and coordination polymers have been well explored. In anticipation of producing an alternate proton-conducting material with superior proton conductivity, both amine and sulfonates were incorporated in a MOF (Cu-SAT). It exhibits high stability in water, stability to dilute hydrochloric acid, and a remarkable proton conductivity of 0.53 × 10–3 S cm–1 at 353 K and 98% RH. As a step toward the practical application of the material in proton exchange membrane fuel cells (PEMFCs), the composite membranes of Cu-SAT and poly(vinylidene fluoride) (PVDF)−poly(vinylpyrrolidone) (PVP) matrix have been further fabricated. These PEMs display a proton conductivity as high as 0.80 × 10–3 S cm–1 at 353 K and 98% RH.