Preparation and characterization of high performance sulfonated poly(p-phenylene-co-aryl ether ketone) membranes for direct methanol fuel cells

•Sulfonated poly(p-phenylene-co-aryl ether ketone)s were prepared as PEM materials.•SPP-co-PAEK CN x membranes displayed good oxidative stability, low methanol permeability and swelling ratio.•SPP-co-PAEK CN 1.86 membrane exhibited comparable cell performance with Nafion@117.

A series of sulfonated poly(p-phenylene-co-aryl ether ketone)s (SPP-co-PAEK) have been designed as membrane materials for direct methanol fuel cell (DMFC) applications. The materials for such membranes have been prepared via the nickel (0) catalyzed coupling copolymerization of 2,5-dichloro-3-sulfobenzophenone and 2,6-bis(4-(4-chlorobenzoyl)phenoxy)benzonitrile. The SPP-co-PAEK membranes show the desired characteristics such as excellent thermal and mechanical properties, good oxidative stability, low methanol permeability and well-defined micro-phase separation. With an ion exchange capacity (IEC) ranging from 1.90 to 2.59 mequiv g−1, these membranes display comparable proton conductivity (0.085–0.170 S cm−1) to Nafion@117 when fully hydrated at 80 °C. In addition, the passive direct methanol fuel cell with SPP-co-PAEK CN 1.86 (IEC = 1.90 mequiv g−1) membrane presents a maximum power density of 24.5 mW cm−2 at 25 °C, which is comparable to the value of Nafion@117 (24.3 mW cm−2).

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