Development of In Situ Formed Metal Pyrophosphates (MP2O7, Where M = Sn, Ti, and Zr)/PA/PBI Based Composite Membranes for Fuel Cells
Development of high temperature polymer electrolyte membrane fuel cells (HT-PEMFCs) at elevated temperatures is important for the enhancement of tolerance toward CO impurities and for the development of non-precious metal catalysts. The key challenge in such HT-PEMFCs is the high temperature polymer...
| Main Authors: | , , , , , |
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| Format: | Journal Article |
| Language: | English |
| Published: |
WILEY-V C H VERLAG GMBH
2023
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| Subjects: | |
| Online Access: | http://purl.org/au-research/grants/arc/DP180100568 http://hdl.handle.net/20.500.11937/94733 |
| Summary: | Development of high temperature polymer electrolyte membrane fuel cells (HT-PEMFCs) at elevated temperatures is important for the enhancement of tolerance toward CO impurities and for the development of non-precious metal catalysts. The key challenge in such HT-PEMFCs is the high temperature polymer electrolyte membranes. Herein, the development of in situ formed metal pyrophosphates (MP2O7, where M = Sn, Ti, and Zr) in phosphoric acid doped polybenzimidazole (PA/PBI) composite membranes for HT-PEMFCs is reported. The formation mechanism of MP2O7, and characteristics of MP2O7/PA/PBI composite membranes are studied in detail. In contrast to the rapid decay in performance of pristine PA/PBI membrane cells, the in situ formed MP2O7/PA/PBI composite membranes show significantly higher proton conductivity, improved performance, and stability at elevated temperatures of 200–250 °C. The best results are obtained on the in situ formed SnP2O7/PA/PBI composite membrane cells, exhibiting a high peak power density of 476 mW cm−2 and proton conductivity of 51.3 mS cm−1 at 250 °C. The excellent durability of SnP2O7/PA/PBI composite membrane is due to the uniform distribution of in situ formed SnP2O7 nanoparticles in PBI membranes and the formation of a gel-like region, thin and irregular amorphous layer on the SnP2O7 with the high acid retention ability. This effectively alleviates the PA leaching at elevated temperatures of the new HT-PEMFCs. |
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