Reaction mechanism of the selective catalytic reduction of NO with NH3 and O2 to N2 and H2O

Semiempirical MSINDO calculations were performed to study the selective catalytic reduction of NO to N-2 on vanadium pentoxide supported by anatase. The active part of the surface was modeled by V2O7 species bound to the anatase (100) surface, which in turn was modeled by a sufficiently large anatase cluster saturated by H and OH groups at the periphery. The whole reaction mechanism consisted of 24 steps and involved NH3, NO and O-2 at the reactant side and N-2 and H2O On the product side. All intermediates and transition structures were optimized under partial relaxation of the surface. The energy profile along the reaction pathway was calculated and it could be shown that the reaction is feasible.