Oxidative dehydrogenation of propane over calcined vanadate-exchanged Mg,Al-layered double hydroxides

Mg,Al-layered double hydroxides (LDHs) exchanged with decavanadate and pyro vanadate 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 intercal ated vanadate. The activity of the calcined decavanadate-exchanged LDH is, depending on temperature, comparable or slightly better than that of the re ference V-Mg-O sample, while its areal activity is much higher, pointing to the formation of centres of higher intrinsic activity. The activity of cat alyst obtained from pyrovanadate-exchanged LDH is low. Selectivity-conversi on profiles indicate that propene formed in the reaction is subsequently ox idized mainly to CO, the process being favoured over catalyst derived from the decavanadate-exchanged LDH, The selectivity pattern is related to the c atalysts acid-base properties. (C) 1999 Elsevier Science B.V. All rights re served.