Influence of tile synthesis parameters on the structural and textural properties of precipitated manganese oxides

A systematic study has been conducted in order to compare the structural and morphological properties as well as the genesis course of manganese oxides prepared by a precipitation-calcination method under different conditions. In particular, the roles of the precursor salt, the pH, the precipitating agent and thermal treatment were investigated. It was found that calcination at 873 K of the starting materials gives rise in all cases to crystalline bixbyite. However, the phases formed at lower temperatures are quite different and depend largely on the synthesis conditions. The systems prepared from a Mn(III) ionic salt present maximum specific surface areas according to a greater development medium-sized pores.