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

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 super(-1), these membranes display comparable proton conductivity (0.085-0.170 S cm super(-1)) to Nafion[at]117 when fully hydrated at 80 [degrees]C. In addition, the passive direct methanol fuel cell with SPP-co-PAEK CN 1.86 (IEC = 1.90 mequiv g super(-1)) membrane presents a maximum power density of 24.5 mW cm super(-2) at 25 [degrees]C, which is comparable to the value of Nation[at]117 (24.3 mW cm super(-2)).