In the present work, the nature of the vanadium species formed on titanium catalysts at different vanadium loading was related to the catalyst behaviour for the deep oxidation of o-dichorobenzene. Chemical physical characterization results indicated that at vanadium loading up to 3% the titanium surface was covered with dispersed V5+ species in tetrahedral and octahedral coordination, while increasing the vanadium content the presence of highly dispersed V5+ species decreased, and additional formation of bulk V2O5 was observed. Catalytic tests indicated that the optimal loading of vanadium was 3%, suggesting that active phases are highly dispersed vanadium species on titania. Moreover, it was observed that incompletely oxidized products, such as dichloro maleic anhydride (2,5 furandione 3,4 dichloro) were formed in all catalysts and the concentration of these by-products increased with vanadium loading. Since the introduction of basic sites on the catalyst surface promoted DCMA formation, this effect was ascribed to the change of acid-basic properties of catalysts due to the increasing of vanadium in the system.
S. Albonetti, S. Blasioli, A. Bruno, J. Epoupa Mengou, F. Trifirò (2005). The effect of the nature of vanadium species on chlorinated organics total oxidation over TiO2 supported catalysts. s.l : s.n.
The effect of the nature of vanadium species on chlorinated organics total oxidation over TiO2 supported catalysts
ALBONETTI, STEFANIA;BLASIOLI, SONIA;EPOUPA MENGOU, JOSEPH;TRIFIRO', FERRUCCIO
2005
Abstract
In the present work, the nature of the vanadium species formed on titanium catalysts at different vanadium loading was related to the catalyst behaviour for the deep oxidation of o-dichorobenzene. Chemical physical characterization results indicated that at vanadium loading up to 3% the titanium surface was covered with dispersed V5+ species in tetrahedral and octahedral coordination, while increasing the vanadium content the presence of highly dispersed V5+ species decreased, and additional formation of bulk V2O5 was observed. Catalytic tests indicated that the optimal loading of vanadium was 3%, suggesting that active phases are highly dispersed vanadium species on titania. Moreover, it was observed that incompletely oxidized products, such as dichloro maleic anhydride (2,5 furandione 3,4 dichloro) were formed in all catalysts and the concentration of these by-products increased with vanadium loading. Since the introduction of basic sites on the catalyst surface promoted DCMA formation, this effect was ascribed to the change of acid-basic properties of catalysts due to the increasing of vanadium in the system.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.