This study reports the preparation of glass membranes doped with CsH5(PO4)2 by an optimized sol - gel method using phosphoric acid as a catalyst for tetraethylorthosilicate (TEOS) hydrolysis and the application of these membranes in intermediate temperature fuel cells (ITFCs). Infrared spectroscopy shows the formation of Si - O - P bonds and scanning electron microscopy shows that the glass membranes have smooth cross-sectional structures. Domains of CsH5(PO4)2 with sizes of 5-12 nm are uniformly distributed over the membrane cross section. The melting point of CsH5(PO4)2 in the glass membrane is lower by 20-40°C than that for pure CsH5(PO4)2. For a glass membrane with a molar ratio of SiO2:CsH5(PO4)2:H3PO4 = 4:1:0.36, 62% of the pore volume is filled with CsH5(PO4)2 and shows the best electrochemical performance. The glass membrane shows high conductivity of 22 mS cm-1 at 219°C. The membrane is novel because the silica support forms an interconnected matrix that provides stability, as shown by continuous operation at 210°C for at least 50 h. A fuel cell assembled with the glass membrane exhibits an open circuit voltage of 0.94 V and a peak power density of 85 mW cm-2. The fuel cell produces a stable output voltage of 0.53 V for at least 50 h under a current density of 100 mA cm-2.
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Energy Engineering and Power Technology
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering