2005

Technology of materialsV 1500 Spontaneous Formation of Macroporous Monoliths of Mesoporous Manganese

Oxide Crystals. — A crystalline single phase Zn1-tMnt(C2O4)·2H2O precursor, ob-tained by coprecipitation from solutions of Zn(OAc)2 and Mn(OAc)2 in aq. oxalic acid, is decomposed in air at 600 °C to an intimate mixture of Zn1-xMnxO and ZnMn2O4. Af-ter pelletizing and sintering the mixture to a more dense monolith, Zn1-xMnxO is re-moved from this monolith by alkali leaching resulting in a macroporous monolith of ZnMn2O4. This monolith, when heated in flowing 5% H2/N2, is reduced to MnO. As revealed by SEM the MnO monolith exhibits a new level of mesoporosity. The final monolith comprises rock salt type MnO with two levels of open porosity in a connected hierarchy. — (TOBERER, E. S.; SESHADRI*, R.; Adv. Mater. (Weinheim, Ger.) 17 (2005) 18, 2244-2246; Dep. Mater., Univ. Calif., Santa Barbara, CA 93106, USA; Eng.) — W. Pewestorf

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