Proton exchange membrane from tetrazole-based poly (phthalazinone ether sulfone ketone) for high-temperature fuel cells

Abstract

Phosphoric acid (PA)-doped proton exchange membranes (PEMs) have been prepared from tetrazole-based sulfonated poly (phthalazinone ether sulfone ketone) (AtSPPESK) for high-temperature proton exchange membrane fuel cells (HTPEMFCs). The polymer structure is characterized by fourier-transform infrared spectroscopy (FT-IR), lH nuclear magnetic resonance (1HNMR) and elemental analysis (EA). Compared with other PEMs only with tretrazole groups in side chains, this membrane with a proper PA doping capacity exhibits a much higher proton conductivity of 15 mS cm−1 at 150 °C. Both of phthalazinone groups in main chains and tetrazole groups in side chains are facial for PA uniform aggregation. To give an insight into the excellent proton conducting performance, therein, a proton transport mechanism has been proposed involving proton transport within hydrogen bonded PA molecules networks as well as acid-base interactions between tetrazole and phthalazinone groups. Meanwhile, the proper oxidative, conductivity, thermal and mechanical stability suggest that the PA doped PEM can hold as a promising membrane for HTPEMFCs.