New methods were used to prepare a nearly stoichiometric Mn3O4 catalys
t. The redox behavior of two kinds of Mn3O4 (i.e. the non- and nearly
stoichiometric Mn3O4) were compared. The relations between the IR para
meters, Mn/O stoichiometry and redox properties of Mn3O4 were establis
hed. It was found that the Mn/O stoichiometry but not IR parameters wa
s closely related to the redox behavior of the compounds.