|
چکیده
|
Abstract: Hydrogen production via electrolysis of water from alkaline aqueous electrolytes is a well-established conventional technology [1-3]. Electrochemical hydrogen compression is seen as a promising alternative to mechanical compression in the context of power-to gas plants. It can be carried out either as direct co-compression in a water electrolyzer or via a separate electrochemical hydrogen compressor. The Water electrolyzer uses electrical energy to split water into oxygen, protons and electrons at the anode [2,4]. Water-cooled stator-winding generators are widely used for large capacity turbine generators of thermal power plant. However, simpler stator cooling system is preferred considering easy operation and maintenance and lower cost. Hydrogen indirectly cooled generator is one of the solution with expansion its capacity[3]. Currently, most electrochemically generated hydrogen is produced using alkaline electrolysers at the alkaline hydrogen electrolysers are used in a wide range of production processes, including the food industry for increasing saturation in oils and fats, their melting points and resistance to oxidation. In addition, the nuclear industry requires H2 for removing O2 as it can cause stress corrosion cracking and power stations use H2 as a coolant for its generators due it its high thermal conductivity. Oxygen, normally considered a by-product of electrolysis[4]. The overall reaction which takes place in a water electrolyser is: ( H2O→ ½ O2 + H2 ) But by change in anode of electrolyzer we can generate ozone instead of oxygen, Ozone is an environmentally-friendly oxidant that is widely used for industrial applications, such as water disinfection, air purification, and medical use[5]. Commercially available technology for ozone generation is based on electrochemistry (water electrolysis: 3H2O→O3 + 6H+ + 6e–) [6]. This approach can be achieved by suitable choice of the anode material to have a high over potential for OER and available couple with cathode to hydrogen generation. In addition to, the material electrode in anode should have good conductance, high durability under drastic operating conditions, and particularly good electrocatalytic activity for ozone production. Different electrodes contain β-PbO2, Pt, Pt composites, boron-doped diamond, TiO2 thin films on Si/TiOx/Pt substrate, and Ti/Ni-Sb-SnO2 catalysts are among the materials that have been used for EOP[5-9]. In this work, a high-performance porous titanium oxide electrode (Ti/TiO2/Ni-Sb-SnO2) has been developed for electrochemical production of ozone. The Ti/TiO2 electrode was prepared using anodizing method at high voltage for forming a layer of porous TiO2 on the surface of Ti mesh, then followed by depositing a layer of Ni-Sb-SnO2 under deep eutectic solvent on the Ti/TiO2 surface. The deep eutectic solvent was used for electrodepositing, because its great effect on electrode performance. Ozone was electro generated from tap water OR alkaline electrolyte on Ti/TiO2/ Ni-Sb-SnO2 electrodes at different operating conditions. Higher efficiency of O3 generation was obtained at 3 V in alkaline electrolyte (Fig. 1).other electrode only with acidic electrolyte exponent to ozone generation but These electrodes were used in electrochemical ozone production (EOP) carried out during the electrolysis of electrolyte-free water or alkaline electrolyte in order to obtain an environmentally friendly technology for water treatment .
|