Manganese(II,III) oxide explained

Manganese(II,III) oxide is the chemical compound with formula Mn₃O₄. Manganese is present in two oxidation states +2 and +3 and the formula is sometimes written as MnO·Mn₂O₃. Mn₃O₄ is found in nature as the mineral hausmannite.

Preparation

Mn₃O₄ formed when any manganese oxide is heated in air above 1000 °C. Considerable research has centred on producing nanocrystalline Mn₃O₄ and various syntheses that involve oxidation of Mn^II or reduction of Mn^VI.^{[1] [2] [3]}

Reactions

Mn₃O₄ has been found to act as a catalyst for a range of reactions e.g. the oxidation of methane and carbon monoxide;^{[4] [5]} the decomposition of NO,^[6] the reduction of nitrobenzene^[7] and the catalytic combustion of organic compounds.^[8]

Structure

Mn₃O₄ has the spinel structure, where the oxide ions are cubic close packed and the Mn^II occupy tetrahedral sites and the Mn^III octahedral sites. The structure is distorted due to the Jahn–Teller effect. At room temperature Mn₃O₄ is paramagnetic, below 41-43 K, it is ferrimagnetic^[9] although this has been reported as reducing in nanocrystalline samples to around 39 K.^[10]

Uses

Mn₃O₄ is sometimes used as a starting material in the production of soft ferrites e.g. manganese zinc ferrite,^[11] and lithium manganese oxide, used in lithium batteries.^[12]

Manganese tetroxide can also be used as a weighting agent while drilling reservoir sections in oil and gas wells.

Notes and References

1. Hausmannite Mn₃O₄ nanorods: synthesis, characterization and magnetic properties Jin Du et al. Nanotechnology, (2006),17 4923-4928,
2. One-step synthesis of Mn₃O₄ nanoparticles: Structural and magnetic study Vázquez-Olmos A., Redón R, Rodríguez-Gattorno G., Mata-Zamora M.E., Morales-Leal F, Fernández-Osorio A.L, Saniger J.M. Journal of Colloid and Interface Science, 291, 1, (2005), 175-180
3. Use of Carbonaceous Polysaccharide Microspheres as Templates for Fabricating Metal Oxide Hollow Spheres Xiaoming Sun, Junfeng Liu, Yadong Li, Chemistry - A European Journal,(2005), 12, 7, 2039 – 2047,
4. The reduction and oxidation behaviour of manganese oxides Stobhe E.R, de Boer A.D., Geus J.W., Catalysis Today. (1999), 47, 161–167.
5. An in situ XRD investigation of singly and doubly promoted manganese oxide methane coupling catalysts.Moggridge G.D, Rayment T, Lambert R.M. Journal of Catalysis, (1992), 134, 242–252,
6. NO Decomposition over Mn₂O₃ and Mn₃O₄. Yamashita T, Vannice A., Journal of Catalysis (1996),163, 158–168,
7. Selective reduction of nitrobenzene to nitrosobenzene over different kinds of trimanganese tetroxide catalysts.Wang W.M., Yang Y.N., Zhang J.Y., Applied Catalysis A. (1995), 133, 1, 81–93
8. Catalytic combustion of C3 hydrocarbons and oxygenates over Mn₃O₄. Baldi M, Finocchio E, Milella F, Busca G., Applied Catalysis B. (1998), 16, 1, 43–51,
9. Magnetic Structure of Mn₃O₄ by Neutron Diffraction Boucher B., Buhl R., Perrin M., J. Appl. Phys. 42, 1615 (1971);
10. Synthesis of superparamagnetic Mn₃O₄ nanocrystallites by ultrasonic irradiation I.K. Gopalakrishnan, N. Bagkar, R. Ganguly and S.K. Kulshreshtha Journal of Crystal Growth 280, 3-4, (2005), 436-441,
11. Method of making manganese-zinc ferrite U.S Patent number: 4093688 (1978)Arthur Withop, Roger Emil Travagli
12. Process for preparing lithium manganese oxides, U.S Patent number: 6706443,(2004), Horst Krampitz, Gerhard Wohner