Studies on the Formation of Some Oxides of Manganese in the Mn⁷⁺-Mn²⁺-OH^- System with Hydrothermal Method

Abstract

The formation conditions of various kinds of oxides of manganese, such as Mn (OH)₂, Mn₃O₄, γ-MnOOH, α-Mn₂O₃, Mn₅O₈, α-MnO₂, β-MnO₂ are studied in Mn₇+-Mn₂+-OH- system with hydrothermal method in a temperature range of 95°C to 270°C. Combination of neutralization, oxidation-reduction and disproportionation reactions gives a reasonable interpretation on the formation mechanism of these compounds.