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用旋转环盘电极研究了亚硒酸在玻碳电极上的阴极行为。在4 mmol/l H_2SeO_3+0.2 mol/l H_2SO_4溶液中,电位比-0.39V稍负,亚硒酸可电化学还原至Se,而当电位比-0.45 V负时,则有H_2Se生成。结果表明,H_2SeO_3电化学还原经历中间历程。电化学还原生成的蓝色硒为电惰性品种,可化学反应生成的红色硒具有电活性。根据电极转速与环、盘电流比值关系导出H_2Se与H_2SeO_1之间的化学反应速度常数为3.2×10~4 l/mol·ε~2。
The cathode behavior of selenious acid on glassy carbon electrode was investigated by rotating ring disk electrode. In 4 mmol / l H 2 SeO 3 + 0.2 mol / l H 2 SO 4 solution, the potential is slightly negative than -0.39 V, selenite can be electrochemically reduced to Se, and H 2 Se is generated when the potential is negative than -0.45 V. The results show that the electrochemical reduction of H 2 SeO 3 undergoes an intermediate process. The blue selenium generated by electrochemical reduction is an electrically inactive species, and the red selenium produced by the chemical reaction is electrically active. The chemical reaction rate constants between H 2 Se and H 2 SeO 1 were deduced from the relationship between the electrode rotation speed and the ring current and disk current. The reaction rate constant was 3.2 × 10 -4 l / mol · ε ~ 2.