Fabrication of Sulfonated Poly Ether Ether Ketone Membranes Reinforced With <scp>PEEK</scp> Meshes: Mos₂ Sputtering to Enhance Functional Properties for <scp>PEM</scp> Water Electrolysis Application

ABSTRACT Membranes play a crucial role in Polymer Electrolyte Membrane Water Electrolysis (PEMWE), a key technology for green hydrogen production. While perfluorosulfonic acid (PFSA) membranes are widely used in commercial PEMWE systems, hydrocarbon‐based membranes are gaining attention due to concerns over fluorine emissions and potential future regulatory restrictions. However, challenges such as swelling and dimensional instability must be addressed for hydrocarbon‐based membranes to be viable alternatives. In this study, a poly(ether ether ketone) (PEEK) mesh and a modified PEEK (MPEEK) mesh, treated with oxygen and molybdenum disulfide (MoS 2 ), were incorporated into a sulfonated PEEK (SPEEK) matrix to fabricate reinforced hydrocarbon‐based membranes. The structural integrity and functional properties of the membranes were investigated. The reinforced membranes exhibited higher tensile strengths, with SPEEK PEEK achieving 43.2 ± 1.6 MPa and SPEEK MPEEK reaching 48.9 ± 1.5 MPa, compared to 34.3 ± 1.4 MPa for the neat SPEEK membrane. Although the incorporation of reinforcement layers led to a reduction in proton conductivity compared to neat SPEEK, this decrease was less pronounced in SPEEK MPEEK membranes (42.5 mS/cm) than in SPEEK PEEK membranes (40.12 mS/cm). This suggests that the modified reinforcement layer in SPEEK‐MPEEK better preserves proton transport pathways, mitigating the conductivity loss. Furthermore, oxidative stability tests using Fenton's reagent demonstrated that membranes reinforced with MPEEK exhibited 86.9% higher resistance to degradation than those with PEEK reinforcement, attributed to the sulfide structures in the MPEEK mesh, which effectively scavenged free radicals. These findings suggest that SPEEK membranes reinforced with MPEEK mesh offer a promising hydrocarbon‐based alternative for PEMWE applications, combining enhanced mechanical strength, decreased swelling ratio, and superior oxidative stability.