Density functional investigation of the mechanism of the selective catalytic reduction of NO by NH3 over vanadium oxide model clusters

Quantum chemical calculations using the density functional theory were performed to model the mechanism of selective catalytic reduction of NO by NH3 on a supported vanadium oxide monolayer. In the first step, the adsorption of NH3 on a bimetallic cluster representative of vanadium oxide, containing a terminal V(DOUBLE BOND)O adjacent to a V(SINGLE BOND)OH group, was investigated. The calculations indicate that NH3 may be strongly adsorbed on V(SINGLE BOND)OH (Brönsted acid site) as NH+4(ads); subsequently, NO reacts with this activated NH3 to yield the reaction products N2 and H2O. The present results give support to a dual-site Eley-Rideal-type mechanism involving a Brönsted site.