Preparation and characterization of manganese oxide catalysts supported onalumina and zirconia-pillared clays

The preparation of manganese oxide catalysts supported (10 wt% MnO2) on pil lared clays is presented. A saponite and a montmorillonite intercalated wit h aluminium and zirconium oligomers and calcined at 500 degrees C, were use d as supports in addition to the starting natural clays. The impregnation w ith manganese(II) nitrate produced a loss of 14-36% of the specific total s urface area of the clays intercalated with aluminium and zirconium polycati ons. Similar tendencies were found for the specific micropore volumes altho ugh the micropore size distributions remained almost unchanged. After calci nation at 500 degrees C, the presence of poorly dispersed beta-MnO2 and alp ha-Mn2O3 has been detected by X-ray diffraction and confirmed by temperatur e-programmed reduction analyses. The results suggested that weak interactio n is established between manganese oxides and the pillared clays. (C) 2000 Elsevier Science B.V. All rights reserved.