Transient kinetics of toluene partial oxidation over V/Ti oxide catalysts

Transient kinetics in the toluene oxidation over V/Ti oxide catalysts prepa red by grafting and impregnation have been compared. V4+ cations are suppos ed to be the sites for the formation of electrophilic oxygen species partic ipating in deep oxidation. Another oxygen species (probably nucleophilic) p resent on the oxidised catalyst surface are responsible for benzaldehyde fo rmation. Selectivity of 80-100% can be obtained during the initial period o f the reaction on the grafted catalysts in the presence of gaseous oxygen a nd during the interaction of toluene (without O-2 in the mixture) with part ially reduced catalysts. (C) 2000 Elsevier Science B.V. All rights reserved .