Catalytic Properties of Cr2O3 Doped with MgO Supported on MgF2 and Al2O3

Abstract

Catalytic properties of Cr2O3 supported on MgF2 or Al2O3 have been modified by magnesium oxide. The catalysts have been obtained by the co-impregnation method and characterised by: BET, XRD and TPR. As follows from the results, the oxides supported on magnesium fluorine react with each other already at 400 °C, leading to formation of an amorphous spinel-like phase. On the Al2O3 support such an MgCr2O4 spinel has appeared at much higher temperatures. The addition of magnesium oxide has a significant effect on the activity and selectivity of the catalysts studied in the CO oxidation reaction at room temperature and in the reaction of cyclohexane dehydrogenation. The magnesium–chromium catalysts supported on MgF2 have been found to show much higher activity and selectivity than the analogous systems supported on Al2O3.