Elaborating conspicuously low hydrogen permeability EVOH composite membrane upgraded by corrosion protection function

Abstract

Developing ultra-high hydrogen barrier composite membrane coupled with corrosion resistance ability is essential to eliminate hydrogen-induced damages in hydrogen delivery and storage. Herein, a unique bottom composite H₂ barrier membrane with the top corrosion protection coating adhered is meticulously designed by a bottom-to-top strategy. Under explicit labour division, the H₂ barrier ability of the bottom Ethylene−vinyl alcohol copolymer (EVOH)/Sericite (Sr)@layered double hydroxide (LDH) membrane can be completely unleashed without fear of corrosive media attacking because of the top fluorinated resin (FEVE)/ordered graphene (Gr) nanosheets corrosion resistance coating. The optimum composite membrane-coating exhibits an exceptionally low H₂ gas transmission rate (GTR) value of 2.373 cm³/(m²·24 h·0.1 MPa), indicating a dramatic 99.98 % reduction compared to pure FEVE and 22 times lower than commercial gas barrier film, attributed to inherent superior gas barrier ability of the pure EVOH and further comprehensive strengthening effect of multi-scaled 2D materials. Considering the pressurized hydrogen environment, the structural and performance changes of the EVOH composite membrane after 8-day 2 MPa hydrogen impact are explicitly investigated both experimentally and theoretically, revealing the crystallinity and regularity of the EVOH polymer chain have been attenuated and the hydrogen accumulation at the interface. High |Z|_0.01Hz value of 2.5 × 10¹¹ Ω cm² throughout 90-day EIS test also suggests outstanding corrosion exemption ability.