Abstract:
99Tc is one of the main fission products in nuclear spent fuel in power reactor. Its halflife period is 213×105 years, which has longterm harm to the ecological environment, and it gets special attention in PUREX process. The chemical properties of rhenium are similar to technetium. Studying the electrochemical behavior of rhenium is of great reference value for understanding the chemical properties of technetium. The electrochemical behavior of perrhenate in sulfuric acid and nitric acid on platinum electrode is studied. The results of cyclic voltammogram and bulk electrolysis with coulometry show that the reduction of ReO-4 ions on the platinum electrode is a multistep electron transfer process, and ReO2 is deposited on Pt electrode. Then the redox reaction of ReO-4/ReO2 will be established. In nitric acid, when the concentration of nitric acid is 100 mol/L, the reduction process of ReO-4 is similar to that in sulfuric acid system. When the concentration of nitric acid is 200, 400 mol/L respectively, nitric is reduced to nitrite by electrochemical reduction, which oxidizes the low valence state rhenium in solution.