Segregation phenomena induced by redox processes in V-Sb-O catalysts

Cation segregation induced by redox processes in a model biphasic V-Sb-O catalyst, containing mildly reduced antimony-deficient vanadium antimonate as a major phase and V(2)O(5)-Sb(2)O(4) solid solution as a minor one, was investigated. It was shown that oxidation caused enrichment of the surface of vanadium antimonate crystals in antimony and reduction, in opposite, resulted in enrichment of these surfaces in vanadium. It was revealed that oxidation and reduction caused vanadium antimonate segregation in large V(2)O(5)-Sb(2)O(4) solid solution crystallites.