Proton Exchange Membrane Water Electrolysis Incorporating Sulfo-Phenylated Polyphenylene Catalyst Coated Membranes

Herein, fully hydrocarbon-based ionomer catalyst coated membranes (CCM)s based on sulfo-phenylated polyphenylene biphenyl (sPPB-H + ) are evaluated in a proton exchange membrane water electrolyzer cell at 70 °C. In conjunction with layers incorporating Nafion® D520 ionomer, sPPB-H require lower applied potential than reference NR112 recast of equal thickness, e.g., 1.66 V vs 1.75 1 A cm −2 . Initially, yield substantially gas crossover compared to the CCMs containing membrane, however, increasing and higher rates voltage evolution is measured during stability test reinforced commercialized similar chemistry (Pemion®) also evaluated, demonstrating smaller changes initial owing mechanical stability. Employment as layer binder investigated, where highest efficiency for all-sPPB-H achieved when anode cathode content 20 wt%, which from electrochemical impedance spectroscopy predominately attributed conductivity within layer. Despite this advancement, high swelling delamination led shorter lifetimes all hydrocarbon non fluorinated electrode assembly, informing future development.