A composite polymer electrolyte membrane includes a composite layer of an aromatic hydrocarbon-based polymer electrolyte and a fluorine-containing polymer porous membrane, wherein a ratio (O/F ratio) of an atomic composition percentage of oxygen O (at %) to an atomic composition percentage of fluorine F (at %) on an outermost surface of the fluorine-containing polymer porous membrane as measured by X-ray photoelectron spectroscopy (XPS) is 0.20 or more to 2.0 or less, and the aromatic hydrocarbon-based polymer electrolyte in the composite layer forms a phase separation structure.

To provide a process for producing an ion exchange membrane for electrolysis which has a low membrane resistance and which is capable of reducing the electrolysis voltage during the electrolysis, even if the membrane strength is increased, an ion exchange membrane for electrolysis, a precursor membrane of an ion exchange membrane for electrolysis, and an electrolysis apparatus.

In a fluorinated polymer having groups convertible to ion exchange groups, a reinforcing fabric 20A formed by weaving covered yarns 21 each comprising a reinforcing fabric 22 and a sacrificial material covering at least a portion of the outer peripheral surface of the reinforcing yarn 22, to produce a precursor membrane of an ion exchange membrane, and from the precursor membrane, at least a portion of the sacrificial material in the reinforcing fabric is eluted to form a reinforcing material and at the same time, the groups convertible to ion exchange groups are converted to ion exchange groups, to produce an ion exchange membrane for electrolysis.

The invention pertains to a process for manufacturing certain (per)fluoroionomer liquid compositions, comprising, inter alia, at least one of fluorination and treatment with a polar solvent, to the liquid compositions therefrom having an improved solids content/surface tension/liquid viscosity compromise, to the use of the same for manufacturing composite membranes and to composite membranes obtainable therefrom.

To provide an ion exchange membrane for alkali chloride electrolysis, which has low membrane resistance and which reduces the electrolysis voltage during alkali chloride electrolysis, even if the spacing between reinforcing yarns is made narrow to increase the membrane strength. This ion exchange membrane 1 for alkali chloride electrolysis comprises a fluoropolymer containing ion exchange groups; a reinforcing material embedded in the fluoropolymer and formed of reinforcing yarns and optionally contained sacrificial yarns; and elution holes of the sacrificial yarns present between the reinforcing yarns, wherein in a cross section perpendicular to the length direction of the reinforcing yarns forming the reinforcing material, the average distance (d1) from the center of a reinforcing yarn 22 to the center of the adjacent reinforcing yarn 22 is from 750 to 1,000 m, the total area (S) obtained by adding the cross-sectional area of an elution hole 28 and the cross-sectional area of a sacrificial yarn 24 remaining in the elution hole 28 is from 500 to 5,000 m.sup.2 per elution hole, and the number n of elution holes 28 between adjacent reinforcing yarns 22 is from 4 to 6.

The present disclosure provides composite ion exchange membranes and methods of making the same. The composite ion exchange membranes of the present disclosure include a first layer comprising a first ion-conducting membrane; a second layer comprising a gas-blocking membrane; and a third layer comprising a second ion-conducting membrane.

A polymer electrolyte composition has excellent practicality and excellent chemical stability as to be able to withstand a strong oxidizing atmosphere during fuel cell operation and is able to achieve excellent proton conductivity under a low-humidified condition and excellent mechanical strength and physical durability, and a polymer electrolyte membrane, a membrane-electrode assembly, and a polymer electrolyte fuel cell produced therefrom. The polymer electrolyte composition includes an ionic group-containing polymer (A), an azole ring-containing compound (B), and a transition metal-containing additive (C), the transition metal being one or more selected from the group consisting of cobalt, nickel, ruthenium, rhodium, palladium, silver, and gold.

A multi-catalytic material that includes a polyelectrolyte membrane and methods of preparing the same are provided herein.

Provided herein are membrane electrode assemblies (MEAs) for CO.sub.x reduction and carbon dioxide reduction reactors (CRRs) that include MEAs.

The invention pertains to a process for manufacturing a fluoropolymer hybrid organic/inorganic composite, to fluoropolymer hybrid organic/inorganic composites obtained therefrom and to the use of the same in several fields of use.

Disclosed are fibers comprising a composition comprising a fluorinated polymer comprising a plurality of ion exchange groups or a precursor thereof and an aromatic polyamide-imide polymer. The fibers are obtained by electrospinning or forcespinning a composition comprising a fluorinated polymer comprising a plurality of ion exchange groups or a precursor thereof and an aromatic polyamide-imide polymer. The fibers can be arranged into webs suitable for the preparation of composite membranes. In particular composite ion exchange membranes suitable for use in proton exchange fuel cells or filtration devices.