A new V2O5-MoO3-TiO2-SO42- nanostructured aerogel catalyst for diesel DeNOx technology

A new V2O5-MoO3-TiO2-SO(4)(2-)nanostructured aerogel system, containing V and Mo loadings representative of the V2O5-MoO3/TiO(2)commercial SCR catalyst, was developedviaa one step sol-gel method combined with the supercritical drying approach for the low temperature selective catalytic reduction of NO by NH3, in excess O-2. The new V2O5-MoO3-TiO2-SO(4)(2-)catalyst was analysedviaXRD, N-2-physisorption, H-2-TPR, NH3-TPD, Raman spectroscopy, XPS and DR UV-vis spectroscopy. The elaboration and characterization of TiO2, V2O5-TiO2, MoO3-TiO2, V2O5-MoO3-TiO2, TiO2-SO42-, V2O5-TiO2-SO(4)(2-)and MoO3-TiO2-SO(4)(2-)aerogel samples were also reported in this work. The results prove the successful synthesis of nanostructured aerogel materials with good crystallinity of the TiO(2)anatase phase, a developed mesoporous texture and a nanometer size as new SCR catalysts. V, Mo and SO(4)(2-)were found to be highly dispersed on the TiO(2)surface, and their presence and the diverse interactions developed between them strongly affect the physicochemical properties and catalytic behaviour of the derived sol-gel powders. Among all the samples investigated, the new V2O5-MoO3-TiO2-SO(4)(2-)aerogel was found to be the most efficient catalyst for the low temperature NO-SCR: compared to a V2O5-WO3/TiO(2)commercial catalyst (EUROCAT), it demonstrates similar SCR activity in the 200-375 degrees C temperature range, but, at higher temperatures (375-500 degrees C), it exhibits superior catalytic performance. A complete conversion of NO into N-2(100%) was achieved in the 450-500 degrees C temperature range over the new V2O5-MoO3-TiO2-SO(4)(2-)nanostructured aerogel catalyst, when the NH3-SCR reaction was realized using 1000 ppm NO and 1000 ppm NH3, in the presence of 3.5% H2O.