Investigation on sulfuric acid sulfonation of in-situ sol–gel derived Nafion/SiO2 composite membrane

✍ Scribed by Chang-Chun Ke; Xiao-Jin Li; Qiang Shen; Shu-Guo Qu; Zhi-Gang Shao; Bao-Lian Yi

• Book ID: 103832953
• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 901 KB
• Volume: 36
• Category: Article
• ISSN: 0360-3199
• DOI: 10.1016/j.ijhydene.2010.12.030

✦ Synopsis

In this paper, an effective method to cover the conductivity loss of Nafion/SiO 2 through sulfonation and its mechanism are studied. Nafion/SiO 2 composite membranes are prepared via an in-situ solegel route, and then sulfonated with concentrated sulfuric acid (marked as Nafion/S-SiO 2 ). The effects of the sulfonation on properties of the Nafion/SiO 2 composite membrane are investigated. The results show that sulfonation can improve the proton conductivity of the Nafion/SiO 2 effectively, though it brings water-uptake loss to the composite membrane to some extent simultaneously. According to the results of FTeIR, UV resonance Raman spectroscopy, 29 Si solid-state MAS NMR and XRD, it's proved that higher conductivity of Nafion/S-SiO 2 should be relevant to hydrogen bonds & chemical bonds between SiO 2 nano particles and sulfuric acid molecules. While, lower water uptake & swelling ratio should be caused by hydroxyl-elimination on the surface of SiO 2 nanoparticles during sulfonation. Single cell tests show that the performance of Nafion/S-SiO 2 composite membranes substantially exceeds Nafion/SiO 2 at 110 C and 59%RH, and in the initial testing stage no performance reduction is observed.