INTRINSIC REACTIVITIES OF MANGANESE OXIDES FOR CARBON-MONOXIDE HYDROGENATION CATALYSIS

A comparison is made between the activities and selectivities of sever al native manganese oxides (MnO, Mn3O4, Mn2O3, MnO2, Cu-MnO2) for carb on monoxide reduction. At 310 degrees C, and 500 psi on feeding synthe sis gas (CO/H-2 = 1/1), the carbon monoxide conversion levels are comp arable but selectivities are quite different. Mn2O3 displays over 90% selectivity for methanol while MnO displays less than 10% selectivity for methanol but over 50% selectivity for carbon dioxide. Patterns of activity and selectivity are discussed for each of the precursors. int erestingly, despite the quite varied selectivities at comparable conve rsion levels, X-ray diffraction on the used catalysts indicates that e ach has been converted to MnO in the bulk as would be expected from th ermodynamics.