(180bs) Highly Aromatic Polymer Containing Quinoxaline Functional Groups for Proton Exchange Membrane Fuel Cells (PEMFCs)

Fuel cells have great promise as environmentally friendly power sources and efficient energy systems. The proton exchange membrane fuel cells (PEMFCs) system consists of the following components: anode, catalyst, PEM, and cathode. PEM plays a central role in fuel cell operation.  In the fuel cell PEMs provide three main contributions: as ion transfer media, for separating reactant gases (hydrogen and oxygen) which react at the cathode and anode, and as a catalyst support. Proton exchange membranes with high ion conductivity, low gas permeability, high thermal stability, and high mechanical strength are desirable. The advantages of PEMFCs that can be operated at high temperature include faster electrochemical reaction, high carbon monoxide tolerance and low catalyst poisoning levels, independent to external humidification system, free of cathode flooding, and high power output which results in smaller unit. New polymers with high glass transition temperature are desired for high temperature and low humidity proton exchange membrane applications. Polyquinoxalines (PQ) are highly aromatic six-membered ring heterocyclic polymer which is an ideal candidate for high temperature PEMs. PQ can be synthesized from aminoaromatic aldehyde and aromatic bisketomethylene groups. One examples of PQ is polyphenylquinoxaline (PPQ). The PPQ glass transition temperature is nearly 300^oC.