Catalytic Reduction of Nitrous Oxide by the Low-Symmetry Pt8 Cluster.

The search for a catalyst for the reduction of nitrous oxide (N2O) is now imperative, as this molecule is a very dangerous pollutant. We found that the low-symmetry Pt8 cluster presents multiple reaction pathways for N2O rupture, which are regioselective. This result was revealed by means of density functional theory calculations within the zero-order-regular approximation, ZORA, explicitly including relativistic effects. It is further proved that Pt8 is a competitive N2O catalyst compared to sub-nanometric rhodium clusters, obtaining similar reaction barriers. The hot adsorption site, a tip atom of Pt8, and the rotation of the N2O molecule over the metallic cluster promote the formation of a frustrated bridge activated transition state, Pt8-N2O. This transition structure yields to spontaneous dissociation of N2O without bridge formation. Along this catalytic process, rearrangements within the metal cluster take place, preserving its stability. Moreover, in addition to being important attributes of the Pt8 particle in the N2O reduction, fluxionality and multiple reaction pathways may also prevent poisoning effects. Overall, this differs from reported results for more symmetric metal particles also used as catalysts.