A theoretical study of isocyanic acid with hydrogen radical (HNCO + OH) catalysed by Au_x (x = 0, 1, 3) cluster: dynamic characterisation

Abstract

The related energy and multi channel HNCO with OH reaction potential energy surface under the catalysis of Au_x (x = 0, 1, 3) cluster and its dynamic characterisation have been investigated with density functional calculations. The geometries were fully optimised with the CCSD(T)//B3LYP level. The calculated results show that the main pathway of the HNCO with OH reaction under the catalysis of Au_x (x = 0, 1, 3) cluster can give the main product P1 (NCO + H₂O), while the minor product is P2 (NH₂ + CO₂). We calculated the rate constant of the main reaction pathway, the calculated dynamic characterisation indicating that the rate constants increase significantly as the temperature increase. According to the dynamic results and the energetically intermediates and transition states involved in the dominant paths, the reaction is expected to be occurred the most rapidly under the catalysis of Au₁. According to our calculation, the singlet atom is the best catalysis and can catalyse the reaction better. The present theoretical studies may provide useful information on the issues of the reaction mechanism and product distributions.

Keywords:

• Dynamic characterisation
• theoretical study
• PES
• rate constant