ESR study of the thermal decomposition of V-containing layered double hydroxides

Heat treatment induced transformations of the ESR signals present in the layered double hydroxides (LDHs) containing vanadium (introduced either as an interlayer decavanadate anion or as a layer-forming cation) are investigated, with particular stress on the changes in the content, electronic structure and symmetry of the vanadyl species created. The differences in the catalytic activity in the oxidative dehydrogenation of propane of the mixed oxide materials resulting from the decomposition of the investigated LDHs are related to the differences in the degree of in-plane pi-covalent bonding observed for V(IV) centres present in these materials. (C) 1999 Elsevier Science B.V. All rights reserved.