Development of proton-conducting membrane based on incorporating a proton conductor 1,2,4-triazolium methanesulfonate into the Nafion membrane

In this paper, 1,2,4-triazolium methanesulfonate (C2H4N+3CH3SO−3, [Tri][MS]), an ionic conductor, was successfully synthesized. It exhibited high ionic conductivity of 18.60 mS·cm−1 at 140°C and reached up to 36.51 mS·cm−1 at 190°C. [Tri][MS] was first applied to modify Nafion membrane to fabricate [Tri][MS]/Nafion membrane by impregnation method at 150°C. The prepared composite membrane showed high thermal stability with decomposed temperature above 200°C in air atmosphere. In addition, the membrane indicated good ionic conductivity with 3.67 mS·cm−1 at 140°C and reached up to 13.23 mS·cm−1 at 180°C. The structure of the [Tri][MS] and the composite membrane were characterized by FTIR and the compatibility of [Tri][MS] and Pt/C catalyst was studied by a cyclic voltammetry (CV) method. Besides, the [Tri][MS]/Nafion membrane (thickness of 65 µm) was evaluated with single fuel cell at high temperature and without humidification. The highest power density of [Tri][MS]/Nafion membrane was 3.20 mW·cm–2 at 140°C and 4.90 mW·cm–2 at 150°C, which was much higher than that of Nafion membrane.

A novel high temperature proton exchange membrane, 1,2,4-triazolium methanesulfonate/Nafion membrane, was developed and showed high ionic conductivity.Figure optionsDownload full-size imageDownload as PowerPoint slide