硫酸溶液中Ag^+离子对Mn^(2+)离子阳极氧化的催化作用

Anodic Oxidation of Mn^(2+) Ion in H_2SO_4 Solutions Catalyzed by Ag^+ Ion

Anodic oxidation of Mn2+ and Ag+ ions and anodic oxidation of Mn2+ ion onplatinum electrode in H2SO4 solution catalyzed by Ag+ ion are studied by using RRDEand triangle voltammetry techniques. Mn2+ ion is oxidized on the anode surface withadsorped OH group to form a certain compound containing Mn3+, which causes Mn2+difficult to be oxidized directly on anode. Near the potential of oxygen evolution fromH2O decomposition, Ag+ ion is oxidized to form Ag2+ ion. This is the main reaction onanode because of its reversability. At higher potential silver oxide is formed on the anode.The oxide catalyzes the decomposition of H2O strongly. The anodic oxidation of Mn2+ion catalyzed by Ag+ takes place and Ag2+ ion and silver oxide are no longer the productof Ag+ anodic oxidation when Mn2+ exists in solution at the potential for Ag+ anodicoxidation. It is confirmed that the catalysis reaction is homogeneous and very fast.