Abstract
Au nanoparticles have been found to possess high reactivity to convert NO into N2O with both high conversion efficiency and selectivity. We have carried out DFT calculations on the reaction mechanism in the reduction of NO to N2O by H2 on the surface of Au4+ and Au4 nanoparticles. The results show that the catalytic cycle proceeds via complexes of Au–H with NO and involves two sequential elementary steps: the rupture of the H–H bond in H2 and the formation of H2O and N2O molecules. On the basis of the calculated potential energy surface profiles, the reaction mediated by cationic nanoparticles is energetically more favourable compared to the neutral cluster, indicating that the activity of Au nanoparticles towards NO reduction is attributable to the concentration of positive charges on the nanoparticles.