Research On Selective Catalytic Reduction Of NO On Vanadium Based Catalysts With Large Surface Area

Vanadium based catalyst is the main catalyst type for denitrification from stationary source.This work discussed the promotion effect of the large surface area anatase TiO2 to the SCR performance of vanadium based catalyst.At the same time molybdenum was added to the system to develop a set of VMoTi catalysts.Several characterization methods were used to study the structure-activity relationship.The results and conclusions were drawn as follows:The large surface area anatase support significantly promoted the dispersion of vanadium species.Catalyst made from this support showed higer NO converstion in the temperature window,and it had a 40% higher NO conversion at 200?.The better structural properties caused vanadium tend to form as V-O-Ti and V=O on the surface.These species enhanced the redox ability and acidity.On the basis of the large surface area support study,a series of catalysts with different V and Mo loading were prepared.Through the optimum recipe 1wt%V2O5-7.5%MoO3-91.5%TiO2 the NO performance selection,the best recipe had a NO conversion of 100% from 250? to 400?.The existence of V promoted the redox ability while Mo provided acidity.In real application,the different working conditions would affect the NO conversion of the catalysts.This thesis systematically studied the effect of GHSV,O2 concentration,NH₃/NO molar ratio and sulfur on catalysts activity.The results showed that at a O2 concentration of 5%,NH₃/NO molar ratio 1:1 condition,the NO conversion was best on the sample.The existence of H₂ O and SO2 did not restrained the activity above 300?.The catalyst developed in this study had a potential practical application.