In recent years, as a result of the increase in global air pollution, hydrogen has more interesting attention as an energy carrier. Hydrogen is a clean and flexible energy carrier that can be used to provide energy and heat in a variety of industries and it is produced from fossil fuels and electrolysis. Electrolysis is known as the cleanest technique for producing pure hydrogen from renewable energy sources. In general, a suitable and satisfactory energy carrier should always be accessible and does not result in substantial energy loss. The hydrogen produced from water electrolysis can be a great option for storing significant amounts of energy. Hydrogen possesses the highest energy specific mass density of all known fuels at present. Oxygen gas is produced by the water oxidation at the anode and hydrogen gas is produced by the reduction of hydrogen ions at the cathode during the water electrolysis process. In this way, the efficacy of hydrogen production is dependent not only on the type of cathode electrocatalyst, but also on the conditions regulating the anode half-reaction and the electrocatalyst used at. This thesis aims to design, synthesis, and eva‎luate an electrocatalyst based on a iridium and ruthenium noble metals that can deliver high efficiency and good stability in the acidic environment and harsh environments (low pH and high potential) of the oxygen evolution reaction. In the first step, after optimizing different various phases of the work, including the selection of the optimized weight percentage of the catalyst relative to the substrate, the duration of stay of the catalyst ink in the ultrasonic bath, and the amount of the catalyst ink to be loaded on the working electrode, the catalysts were prepared. 80wt.% electrocatalysts in this study are composed of iridium and ruthenium noble metal oxides, and a mixture of the two oxids with a ratio of 60:40 iridium oxide to ruthenium oxide, on nanoparticles and nanotubes of titanium oxide as catalyst support. P25 titanium oxide nanoparticle substrates and electrochemically synthesised titanium oxide nanotubes from titanium sheets were used to synthesise catalysts using a modified Adams fusion method. In this study, the catalysts were divided into two groups for a comprehensive analysis. Catalysts based on iridium oxide belong to the first group, while catalysts composed of iridium oxide and ruthenium mix oxides belong to the second group. To determine the composition of the catalysts, variuos techniques were used, including X-ray diffraction analysis, transmission electron microscopy, and X-ray photoelectron spectroscopy. The activity of catalysts was assessed using cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy techniques. The stability eva‎luation was conducted in a thorough manner via the use of cyclic voltammetry, as well as chronopotentiometric and chronoamperometric tests. The results from the eva‎luation of the activity of the catalysts in the first series showed that the IrO2/TNT catalyst exhibited a total voltammetric charge of 2958.43 mC mgIr-1, a value almost six times higher than that of the IrO2 catalyst without a substrate, which measured at 502.85 mC mgIr-1. The use of TNT substrate for IrO2 resulted in a significant enhancement in mass activity, as seen by an increase from 25.25 mA mgIr-1 for IrO2 without substrate to 109.42 mA mgIr-1 for IrO2/TNT at 1.60 V. The TEM images showed a reduction in the mean diameter of IrO2 particles, decreasing from 13.30 nm to 7.90 nm in the case of IrO2/TNT. Additionally, the results of stability tests indicated that IrO2/TNT exhibited enhanced durability compared to other samples. When assessing the performance of the catalysts in the second series, the IrRuOX/TNT particles exhibited a total charge of 3647.50 mC mg-1 of noble metal and an average diameter of 7.85 nm.

محمد ژياني

حسن حداد زاده , محمد محمدي تقي آبادي

كيوان رئيسي , محمدمحسن مومني هامانه , اسماعيل شمس سولاري