Theoretical investigation of the mechanism of indirect decomposition of nitrous oxide (N2 O) by hydrogen (H2 ) on Cu7 cluster

Abstract Mechanism of the decomposition reaction between N 2 O and H 2 molecules on the Cu 7 cluster was studied using density functional theory (DFT) with the BP86 functional in combination with the Aug‐cc‐pVDZ basis sets for N, O and H atoms, and the cc‐pVDZ‐PP basis set for Cu atom. The results show that the reaction undergoes via two successive steps. The first step involves adsorption of N 2 O on the Cu 7 surface, followed by the decomposition of N 2 O with an energy barrier of barely ~3 kcal/mol, producing an O atom, which subsequently binds to the cluster and a N 2 molecule. In the second step, the adsorped O atom couples with the H 2 molecule bound to a different Cu atom of the cluster leading to a release of H 2 O molecule via two different pathways. The pathway corresponding to an adsorption of a N 2 O molecule onto the most positively charged site of Cu 7 as turns out that the most energetically favorable with an energy barrier of ~22 kcal/mol, which is much lower than the barrier of 42 kcal/mol for the reaction without a catalyst.