Complete oxidation of acetone over manganese oxide catalysts supported on alumina- and zirconia-pillared clays

The complete oxidation of acetone has been studied over a series of manganese oxide catalysts supported on the unpillared and the Al- and Zr-pillared forms of two natural clays of the smectite class (a montmorillonite and a saponite). The temperatures required for total combustion of acetone over the several catalysts ranged from 610 to 660 K at the relatively low W_Mn/F_in ratio of 0.40 g_Mn min mmol_acetone⁻¹ used. A significant influence of the clay supports characteristics on the catalytic performance has been found. According to the general behaviour of the various catalysts throughout the light-off tests, the following order of improving catalytic performance can be established with respect to the pillars composition: Al-pillared clays2O₃, MnO₂, Al₂O₃ and ZrO₂, as well as physical mixtures of ZrO₂ with the unpillared clays. The effect on the catalytic performance of the possible competition between the acetone combustion and aldol condensation processes has also been considered.