THERMALLY STABLE CAO SURFACES ON HIGHLY DISPERSED MGO - NEW ASPECTS FOR METHANE ACTIVATION

Chemical Vapour Deposition (CVD), applied to the production of mixed o xides of magnesium and calcium, provides nanostructured particles with outstanding surface properties which are dominated by low coordinated sites and CaO enrichment. The resulting basic material should, theref ore, be particularly well suited for methane activation. In addition, it turned out to be extremely thermally stable. In fact, FTIR spectros copy clearly evidences efficient methane chemisorption on the new oxid e material. EPR spectroscopy indicates the presence of new paramagneti c centres after the addition of methane. - If the mixed oxide samples are exposed to UV irradiation (> 320 nm) in the presence of a methane/ oxygen mixture, IR bands appear which have to be attributed to larger homologous alkyl structures which are - for different reasons not obse rved on the pure constituents (MgO, CaO). Thus relevant implications o f the new oxide material are to be expected in the field of heterogene ous catalysis, in particular, of Oxidative Coupling of Methane (OCM).