FTIR STUDIES ON THE SELECTIVE OXIDATION AND COMBUSTION OF LIGHT-HYDROCARBONS AT METAL-OXIDE SURFACES .2. PROPANE AND PROPENE OXIDATION ON CO3O4

The interaction of propane and propene and of C-3, C-2 and C-1 oxygena tes (propan-1-ol, propan-2-ol, allyl alcohol, acetone, propanal, acrol ein, acrylic, propionoic, acetic and formic acids and CO2) on oxidized Co3O4+x has been studied by FTIR spectroscopy, with the aim to collec t data on the mechanism of hydrocarbon catalytic combustion. Propene i s already oxidized to acrylate species at RT and burns completely star ting from 473 K. Propane already gives rise to acetate, propanoate and acrylate species below 373 K. A reaction scheme for catalytic propane oxidation is proposed. The behaviour of Co3O4+x combustion catalyst s urfaces are compared with those of MgCr2O4+x, previously investigated. In both cases nucleophilic oxygen species (lattice O2- anions at the oxidized surface) are thought to be involved in catalytic combustion, which occurs via overoxidation of adsorbed partially oxidized compound s.