Experimental investigation of sulfonated poly(ether ether ketone) ionomer in the catalyst layer of proton exchange membrane fuel cell (PEMFC)

As a key component of electrode, the electrode ionomer forms the ionomer network in the catalyst layer and causes change of the pore structure in the catalyst layer; it has a great influence on catalyst utilization and gas transfer to the catalyst. So introduction of new electrode ionomer would have a significant effect on cell performance. Sulfonated poly (ether ether ketone) (sPEEK) is one of the ionomers that can be used. In this study sPEEK was prepared by the sulfonation of PEEK. The degree of sulfonation was determined 61% by H-NMR. Then, it was used as ionomer in electrode to investigate the influence of different content of iononmer on electrode. Cyclic voltammetry experiments were performed to determine electrochemically active area (ECA) of electrocatalyst. In 25 weight percent of sPEEK ionomer in the catalyst layer, electrochemical active area is maximum