Water electrolysis with Zirfon® as separator and NaOH as electrolyte

Composite membranes are aimed at employing and enhancing some characteristics of the two materials they consist of: organic and inorganic materials. In this research work, a member of the composite membrane family, Zirfon®, was studied. This material consists of a polysulphone matrix and zirconium oxide, in the form of powder. The presence of zirconium oxide improves the wettability of the material, an important issue if the process includes the evolution of gaseous products as in water electrolysis. Zirfon® was tested in a crystal acrylic electrolytic cell with rectified blocks, which established the different distances between electrodes. The material selected for the cathode and the anode was stainless steel 316 L. In this experience, 20% w/w NaOH was used as electrolytic solution at room temperature. The experiment was carried out by applying a range of differential potential to the electrolytic cell. Six different distances between electrodes were studied: 7.5, 6.5, 5.6, 4.45, 4.25 and 3.10 mm. The control parameters were current, voltage and temperature. These parameters allowed us to calculate the following: decomposition voltage, resistance and conductance of the electrolytic solution. Resorting to this data set, the distance between electrodes selected was 3.10 mm, where the best performance of the system is obtained.