| Titanium-based metal oxide anodes are prepared by coating a noble metal oxide coating on titanium substrate. They have been broad used in Chlor-alkali industry, electrochemical pollution, cathodic, protection and other areas. The anode of Ti/RuO2-IrO2-SnO2with excellent electrocatalytic activity and electrochemical stability is an excellent anode which is using in the seawater electrolysis antifouling. Temperature and concentration of electrolyte influence activity and durability of anode in actual engineering, especially in the low temperature of seawater.The Ti/RuO2-IrO2-SnO2anode coated on titanium was prepared by thermal decomposition, which was studied the effect of temperature of seawater, concentration of NaCl, temperature of H2SO4. Morphology, surface composition and crystal structure of deactivation behavior were characterized by means of SEM, EDX and XRD. The cyclic voltammetry, polarizing curve measurement, electrochemical impedance spectroscopy were tested to analyze deactivation behavior and deactivation mechanism.The electrochemical properties of Ti/RuO2-IrO2-SnO2anode affected by temperature of seawater were studied. The results show that the cyclic voltammogram of charge of metal oxide anode would be smaller and its activity would be restricted at low temperature. Chlorine evolution potential rise and current efficiency of chlorine evolution reduce with temperature decrease. Chlorine evolution become difficult and metal oxide anode performance significantly decrease at low temperature.The accelerated life of anodes affected by temperature of seawater and H2SO4were studied, it was found that the life of anode would shorten with temperature of seawater decrease. Life of anode significantly affected by low temperature and anode would be inactivated in low temperature.Invalidation mechanism of anode at40℃seawater is not the same with invalidation mechanism of anode at low temperature seawater. Anode surface which inactivated in low temperature failure appears obvious boundaries. The results indicated that the center of the deactivated anodes electrolysed at5℃～20℃had traces of coating with dried-mud cracks remained while the surrounding area at the edge exposed the bare titanium substrate, which was caused by the dissolution of the active components, and the peeling of the coating. When the electrolysis temperature of seawater is40℃, the consumption of the coating by electrochemical dissolution of the active components was uniform in the coating. In addition, the electrochemically active surface area and the stability of the anode increase with the rising of the temperature. The deactivation of the anode at5℃～20℃is selective dissolution of Ru and partial detachment of the coating, and the deactivation of the anode at40℃was the formation of TiO2between Ti and the active coating. The effect of temperature of H2SO4on accelerated electrolysis life tests was studied, which was found different with affected by temperature of seawater, the accelerated electrolysis life would decrease with temperature of H2SO4increase.The electrochemical properties and accelerated electrolysis life of Ti/RuO2-IrO2-SnO2anode affected by concentration of NaCl were studied, which was found that chlorine evolution potential decrease and current efficiency of chlorine evolution rise with concentration of NaCl increase. The accelerated electrolysis life of Ti/RuO2-IrO2-SnO2anode affected by concentration of NaCl was obvious. The accelerated electrolysis life of anode was only50h in1%NaCl solution, but the accelerated electrolysis life of anode was350h. |
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