Preparation and characterization of novel pyridine-containing polybenzimidazole membrane for high temperature proton exchange membrane fuel cells

• Published in: Journal of membrane science 2016-03, Vol.502, p.29-36
• Main Authors: Fang, Jun, Lin, Xia, Cai, Di, He, Na, Zhao, Jinbao
• Format: Article
• Language: English
• Subjects: 4,4′-(pyridine-2,6-diylbis(oxy))dibenzoic acid (PDA); Ethers; High temperature fuel cells; Ion exchangers; Membranes; PDA; Polybenzimidazole (PBI); Polybenzimidazoles; Polymerization; Proton exchange membrane; Proton exchange membrane fuel cells; Pyridine; Pyridines
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2015.12.006

A novel pyridine-containing polybenzimidazole (PDA-PBI) membrane was developed as a candidate for high-temperature polymer electrolyte membrane fuel cells. Aiming to improve the solubility and proton conductivity of the ionomer, a diacid monomer, 4,4′-(pyridine-2,6-diylbis(oxy))dibenzoic acid (PDA), was synthesized and condensation polymerized with 3,3′-diaminobenzidine (DAB) to prepare a polymer containing ether groups and pyridine rings. The soluble PDA-PBI membranes were prepared by solution casting method and then soaked in phosphoric acid solution. The polymers were characterized by Fourier transform infrared spectroscopy, element analysis and thermogravimetric analyses. The PDA-PBI has good thermal stability with onset decomposition temperature up to 350°C. The proton conductivity of the prepared membrane is 11mScm−1 at 25°C and 83mScm−1 at 160°C without any humidification. The evaluations of fuel cell performance were conducted using the PDA-PBI membranes and a peak power density of 460mWcm−2 was obtained at 160°C with unhumidified hydrogen and oxygen. •A novel PDA-PBI membrane was prepared for high-temperature PEMFCs.•The PDA-PBI polymer can be dissolved in NMP and DMSO at room temperature.•The proton conductivity of the PA doped membrane was 83mScm−1 at 160°C.•Fenton test results show the membrane possesses reasonable oxidative stability.•A peek power density of 460mWcm−2 of fuel cell was obtained at 160°C.