Preparation of silica-based proton conductors for intermediate temperature fuel cells

Abstract

The ternary system SiO 2 -P 2 O 5 -ZrO 2 electrolyte and phosphotungstic acid (PWA) doped SiO 2 -P 2 O 5 -ZrO 2 electrolyte were prepared for intermediate temperature fuel cell by using sol-gel technique. These silica-based proton conductors were confirmed to be non-crystalline structure without phase separation and good thermal stability by XRD and TG/DTA analysis. The doped PWA was found to be stabilized within the silica matrix and to enhance the proton conductivity. The proton conductivities of SiO 2 -P 2 O 5 -ZrO 2 and SiO 2 -P 2 O 5 -ZrO 2 -PWA electrolytes showed 3.3×10 −5 and 1.8×10 −3 S/cm at 90 o C, respectively, and the cell performance of SiO 2 -P 2 O 5 -ZrO 2 -PWA electrolyte was obtained as 0.02-0.25 mA/cm 2 at 300 o C under humid condition.

Enhanced Oil Recovery in Low-Permeability Reservoirs Utilizing Dispersions of Monodisperse Crumpled SiO2 Nanoparticle

“…It possessed a rich micropore structure with a large surface area and relatively low density, making it suitable for surface modification. 21 As shown in Figure 5b, the nitrogen adsorption−desorption isotherms of both types of SiO 2 exhibited typical type IV isotherms with H 3 hysteresis loops, indicating the presence of mesoporous structures in both nanomaterials. The specific surface areas of C-SiO 2 and S-SiO 2 were 681.16 and 145.23 m 2 /g, as calculated using the BET method.…”

“…Amorphous SiO 2 was characterized by a noncrystalline structure with a well-developed three-dimensional network and capillary pores. It possessed a rich micropore structure with a large surface area and relatively low density, making it suitable for surface modification . As shown in Figure b, the nitrogen adsorption–desorption isotherms of both types of SiO 2 exhibited typical type IV isotherms with H 3 hysteresis loops, indicating the presence of mesoporous structures in both nanomaterials.…”