CATALYTIC-OXIDATION OF PROPENE OVER SB-SN-O MIXED OXIDES

The surface composition of Sb-Sn-O mixed catalysts has been investigated by Auger electron spectrometry. The results show a surface enrichment in antimony upon calcination, which is consistent with previous XPS analysis. AES can therefore be used to study the surface of real catalysts, provided a low intensity for the primary beam is used. The selectivity for the oxidation of propene to acrolein changes with the temperature at which the reaction is performed, and the variations depend on the temperature of the calcination step in the preparation of the catalyst. A discussion is presented of the two classes of catalysts that appear.