Ordered mesoporous; Mn2O3 and I Mn3O4 with crystalline walls (see figure) have been successfully synthesized. Mesoporous Mn2O3 was converted to Mn3O4 in a reducing atmosphere without destroying the ordered mesostructure, which gives the first example of mesoporous Mn3O4 or any reduced mesoporous manganese oxide, something that is unlikely to be achieved by direct template synthesis.