A solid-state ion-exchange method is described that introduces vanadium into zeolites BZSM-5, BBeta and their deboronated by washing forms at 773 K in hydrogen. Two types of vanadium species (vanadium ions in cationic position and VO2+ complex in a silanol nest) are identified when the amount Of V2O5 is equivalent to the framework boron. The vanadium-loaded samples have been characterised by the methods of IR-KBr, FTIR and UV-Vis spectroscopies; temperature-programmed reduction/oxidation cycles (TPR/TPO). (C) 2004 Elsevier B.V. All rights reserved.