PAF-6 Doped with Phosphoric Acid through Alkaline Nitrogen Atoms Boosting High-Temperature Proton-Exchange Membranes for High Performance of Fuel Cells

Liying Wang; Yuliang Wang; Zhangnan Li; Tianyang Li; Ruyu Zhang; Jing Li; Baijun Liu; Zhongyuan Lv; Weiwei Cai; Shuhui Sun; Wei Hu; Yunfeng Lu; Guangshan Zhu

doi:10.1002/adma.202303535

PAF-6 Doped with Phosphoric Acid through Alkaline Nitrogen Atoms Boosting High-Temperature Proton-Exchange Membranes for High Performance of Fuel Cells

Adv Mater. 2023 Aug;35(33):e2303535. doi: 10.1002/adma.202303535. Epub 2023 Jul 6.

Authors

Liying Wang¹, Yuliang Wang¹, Zhangnan Li¹, Tianyang Li², Ruyu Zhang¹, Jing Li³, Baijun Liu², Zhongyuan Lv², Weiwei Cai³, Shuhui Sun⁴, Wei Hu¹, Yunfeng Lu^{5

6}, Guangshan Zhu¹

Affiliations

¹ Faculty of Chemistry, Northeast Normal University, 5268 Renmin Street, Changchun, 130024, P. R. China.
² Faculty of Chemistry, Jilin University, 2699 Qianjin Street, Changchun, 130012, P.R. China.
³ Faculty of Materials Science and Chemistry, China University of Geosciences, 388 Lumo Road, Wuhan, 430074, P. R. China.
⁴ National Institute of Scientific Research (INRS) Center Energy Material and Telecommunications, Varennes, Quebec, J3×1P7, Canada.
⁵ Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, P. R. China.
⁶ Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA, 90095, USA.

PMID: 37358077
DOI: 10.1002/adma.202303535

Abstract

High-temperature proton-exchange-membrane fuel cells (HT-PEMFCs) can offer improved energy efficiency and tolerance to fuel/air impurities. The high expense of the high-temperature proton-exchange membranes (HT-PEMs) and their low durability at high temperature still impede their further practical applications. In this work, a phosphoric acid (PA)-doped porous aromatic framework (PAF-6-PA) is incorporated into poly[2,2'-(p-oxydiphenylene)-5,5'-benzimidazole] (OPBI) to fabricate novel PAF-6-PA/OPBI composite HT-PEMs through solution-casting. The alkaline nitrogen structure in PAF-6 can be protonated with PA to provide proton hopping sites, and its porous structure can enhance the PA retention in the membranes, thus creating fast pathways for proton transfer. The hydrogen bond interaction between the rigid PAF-6 and OPBI can also enhance the mechanical properties and chemical stability of the composite membranes. Consequently, PAF-6-PA/OPBI exhibits an optimal proton conductivity of 0.089 S cm^-1 at 200 °C, and peak power density of 437.7 mW cm^-2 (Pt: 0.3 mg cm^-2 ), which is significantly higher than that of the OPBI. The PAF-6-PA/OPBI provides a novel strategy for the practical application of PBI-based HT-PEMs.

Keywords: OPBI; fuel cells; high-temperature proton-exchange membranes; porous aromatic frameworks; proton transfer.

Abstract

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