The instant method produces Mn(III) and Mn(VII) in stabilized form. Stabilized Mn(II), Mn(III), Mn(IV), and Mn(VII) are also formed on solid supports. Solid supported Mn(VII) is prepared by first reacting an H-saturated support with Mn(II) in solution. Mn(III) substituted Fe oxide coated on natural zeolite (FMNZ) is prepared by reacting Mn(II) and Fe(III) to a natural zeolite equilibrated with 2 N NaoH. The resulting Mn(IV) and Mn(III) oxide is precipitated from solution and dried to give supported Mn(IV) or Mn(III). The Mn(IV) material is reacted with 1,4-phenylenediamine (PDA) to form supported Mn(VII). In another aspect of the invention, Mn(II) is synthesized by adding 1,2-phenylenediamine dihydrochloride to uncoated and clay and-zeolite coated MnO₂. Mn(II) and Mn(III) are synthesized by adding 1,2-phenylenediamine dihydrochloride and 1,4-phenylenediamine dihydrochloride, respectively, to uncoated Mn containing clays, and clay and-zeolite coated MnO₂.