In-situ observation for the reaction of hydrogen peroxide in high temperature water utilizing electrochemical impedance spectroscopy

Direct observation of the reaction of H2O2 at the surface of stainless steel was performed by electrochemical impedance spectroscopy (EIS) in high-purity water at 288 degrees C. From this, the corrosive conditions and behavior of stainless steel in high-temperature and high-purity water containing H2O2 were determined. The results obtained could be summarized as follows: 1) The EIS data were directly measured in high-temperature water without electrolyte injection. 2) The conductivity of the high-temperature water at 288 degrees C, calculated by R-sol, was 8.3 x 10-6 S/cm. 3) R-p was 9.0 x 10(3) ohm.cm(2) for 100 ppb of injected H2O2, and the estimated corrosion rate was about 30 mu m/year. 4) The reciprocal of the polarization resistance had a linear relationship with the H2O2 concentration, indicating that the corrosion current is determined by the cathodic reaction of H2O2. 5) The estimated DH2O2 was 1.5 x 10(-4) cm(2)/s.