most promising alternatives for Nafion, the industry benchmark for electrolytic membranes in
proton exchange membrane (PEM) fuel cells. In the present study, PEEK was non-
homogeneously sulfonated using concentrated H2SO4 at different temperatures (room
temperature, 60° C, and 80° C) and time durations (5, 7, 48, and 72h). Composite
membranes of SPEEK with different weight ratios of AlPO4 synthesized by sol–gel were also …