A Mild Method for the Activation of Cation Exchange Membranes Used in Tubular PEM Electrolyzers

Co-extrusion of both half-cells in tubular PEM water electrolyzers can lower the costs for hydrogen production, since the number of components is reduced and the production process is simplified. However, after co-extrusion of the inner half-cell and the ion exchange membrane, the membrane is in its fluoride sulfonyl form and must be hydrolyzed to achieve the proton conductive sulfonic acid to be ready for use. Common practice is the hydrolysis using concentrated alkaline solutions, which causes a corrosion of the laminated anode electrode. We developed a less corrosive method using triethylsilanol as reactant. Tubular membranes hydrolyzed with this new procedure were characterized and tested in an electrolyzer laboratory test setup. PEM tubular membranes are extruded directly onto a tubular electrode. After the extrusion its fluoride sulfonyl groups have to by hydrolyzed. We developed a less corrosive method using the SuFEx reaction to produce the sulfonic acid groups. The membrane was characterized concerning its properties in comparison to a commercial membrane, and it was tested in a tubular PEM water electrolysis single cell. image