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

High Temperature PEM Fuel Cells Based on Nafion®/SiO2 Composite Membrane

“…In our previous work (Ke, Li et al 2010;Ke, Li et al 2011), a technique in controlling silicate nanoparticle diameter in preparation of Nafion/SiO 2 composite membranes was put forward. The detailed process is shown as follows.…”

“…(a) FT-IR spectra of Nafion, Nafion/SiO 2 and sulfonated Nafion/S-SiO 2 composite membranes; (b) FT-IR spectra of sol-gel derived SiO 2 and the sulfonated S-SiO 2 . (Ke, Li, et al, 2011) 3.2 UV Raman spectra UV resonance Raman spectra were recorded at room temperature using a home-made UV resonance Raman spectrograph of State Key Laboratory of Catalysis (Dalian institute of Chemical Physics) at a resolution of 2 cm -1 . The laser line at 325 nm of a He-Cd laser was used as an exciting source with an output of 25 mW.…”

“…UV Raman spectra of sol-gel derived SiO 2 and the sulfonated S-SiO 2 . (Ke, Li, et al, 2011) It is well known, the scattering peaks at ~620 cm -1 and 873 cm -1 could be attributed to the so called D2 defect structure (strained three-membered rings) and strained 2-fold rings (edgesharing tetrahedra) respectively (Brinker, Kirkpatrick et al 1988), which form primarily on the silica surface by condensation reactions involving isolated adjacent silanol groups (Brinker, Tallant et al 1986). After sulfonation, the ~620 cm -1 and 873 cm -1 peaks disappear, suggesting that a reverse reaction of surface condensation occurs during sulfonation.…”

“…Water uptakes of Nafion, Nafion/SiO 2 and Nafion/S-SiO 2 composite membranes sulfonated for 4h, 10h, and 16h. (Ke, Li, et al, 2011) The water uptakes of Nafion, Nafion/SiO 2 , Nafion/S-SiO 2 -4h, Nafion/S-SiO 2 -10h, and Nafion/S-SiO 2 -16h at 40, 60, and 80 °C are shown in Figure 3. It shows that the Nafion/SiO 2 has a higher water uptake than the unmodified Nafion at the considering temperature region.…”

“…Proton conductivities of Nafion, Nafion/SiO 2 and Nafion/S-SiO 2 composite membranes sulfonated for 4h, 10h, and 16h. (Ke, Li, et al, 2011) …”