Abstract
Mg,Al-layered double hydroxides (LDHs) exchanged with decavanadate and pyrovanadate anions have been prepared and characterized by elemental analysis, FTIR, PXRD, XPS and BET. The mixed oxide materials obtained by calcination at 823
K differ in catalytic performance depending on the type of intercalated vanadate. The activity of the calcined decavanadate-exchanged LDH is, depending on temperature, comparable or slightly better than that of the reference V–Mg--O sample, while its areal activity is much higher, pointing to the formation of centres of higher intrinsic activity. The activity of catalyst obtained from pyrovanadate-exchanged LDH is low. Selectivity-conversion profiles indicate that propene formed in the reaction is subsequently oxidized mainly to CO, the process being favoured over catalyst derived from the decavanadate-exchanged LDH. The selectivity pattern is related to the catalysts acid–base properties.