Enhancement of Phosphoric Acid-Functionalized Graphene Oxide on SPEEK Membrane Performance

Abstract

Sulfonated poly ether ether ketone (SPEEK) membrane has a great potential in the application of proton exchange membrane fuel cells owing to low cost. However, it suffers from limited proton conductivity. In this paper, quantum chemistry calculation and molecular dynamics simulation are employed to reveal the enhancing mechanism of phosphoric acid-functionalized graphene oxide (GO) on proton conduction in the SPEEK membrane. The results reveal that the strong interaction between sulfonic acid group and phosphoric acid group leads to the dissociation of proton and the proton transfer pathway with a low energy barrier is formed. Meanwhile, it is found that the phosphoric acid-functionalized GO can interact well with water molecule and membrane matrix so as to promote the transport of water molecules in the membrane.