Zn(Ⅱ)-Based Metal-Organic Framework/Nafion® Composite Membrane with High Proton Conductivity for Fuel Cell Applications

H.J. Kim, L. Kabir and S-J. Cho
Kyungpook National University, Daegu 41566, Korea,

Keywords: PEMFC, Coordination network, MOF, Proton Conductivity, Nafion


Metal-organic frameworks (MOFs) can serve as a scaffold to anchor acidic groups and provide efficient proton transfer pathways owing to their highly ordered structures and modular nature. Intentional coordination of MOFs with a conductive polymer was targeted to improve the proton conductivity and propose a better candidate material for fuel cell applications. Employing the concept of coordination networks, the conductivity of Nafion® was amplified by fabricating a composite of it with an inexpensive and highly proton-conductive three-dimensional MOF, namely, {[(Me2NH2)3(SO4)]2[Zn2(ox)3]}n (1, Me = methyl, ox = oxalate). Along with slightly higher thermal stability, increased ion exchange capacity (IEC) and water uptake were observed, and the addition of 1 wt% of MOF 1to Nafion® was found to be maximally efficient. The MOF structure was confirmed by field-emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) analysis, while the MOF 1/Nafion® composite was characterized using Fourier transform infrared spectroscopy (FT-IR). This study may offer a cost-effective and facile fabrication technique for a variety of proton exchange membranes with characteristic proton-conducting properties for fuel cell applications.