Selective catalytic reduction of nitric oxide over vanadia grafted on titania. Influence of vanadia loading on structural and catalytic properties of catalysts Article uri icon

abstract

  • The selective catalytic reduction (SCR) of NO by NH3 has been studied over vanadia/ titania catalysts prepared by selective immobilization of vanadyl alkoxide species on two structurally different titania supports. The loading of vanadia was varied from 1.8 to 7.5 μ,mol V5%2b per m2 surface area. Comparative kinetic measurements at 150 °C show that the NO turnover frequencies increase by more than an order of magnitude when the vanadia loading is increased from 1.8 to ≈ 3 μmol V5%2b/m2. In the region of lower SCR activity, i.e. at lower coverages (≈ 2 μmol V5%2b/m2), small clusters and ribbons of vanadia are detected in the Raman spectra, whereas at loadings where maximum NO turnovers are achieved (≈ 3 μmol V5%2b/m2) the prevalent vanadia species are well-developed two-dimensional vanadia layers bound to titania. © 1992 J.C. Baltzer A.G. Scientific Publishing Company.

publication date

  • 1992-01-01