Terphenyl pyridine based polymers for superior conductivity and excellent chemical stability of high temperature proton exchange membranes

Abstract

A series of novel poly(terphenyl pyridine) polymers are synthesized from 4-acetylpyridine, p-terphenyl, and comonomer 2,2,2-trifluoroacetophenone via the acid-catalyzed polycondensation reaction. After doped with phosphoric acid (PA), the prepared membranes exhibit proton conductivity as high as 0.142 S cm−1 at 160 °C under anhydrous condition. This membrane-based single fuel cell show a peak power density of 395 mW cm−2 at 180 °C by fueling with non-humidified H2 and O2. A reasonable tensile stress at break of about 10 MPa is reached by the acid doped membranes under ambient atmosphere. Exposed in the Fenton reagent (3 wt% H2O2, 4 ppm Fe2+) at 68 °C for up to 1000 h, the membrane can still maintain original strength and possess affinity to acid molecules. After suffered the Fenton test at 68 °C for 200 h, the membrane is doped with PA to prepare membrane electrode assembly, which endows the single fuel cell with a power density of 206 mW cm−2 at 180 °C feeding with non-humidified H2 and O2.