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.

The relative stability and kinetics of CH4 … O2 … MO and the reaction potential energy surface under the transition metal oxide catalysts (RuO/RhO/PdO) during methane oxidation reaction were studied with density functional calculations. The results show that the reaction can be easily carried out under the catalysis of transition metal oxides. The transition barriers and the reaction rate constant all show oscillation modes that are consistent with the increase of atomic number at 298 K. while the calculated reaction energies (Er/kcal mol−¹) are gradually increased. The oxidised dioxide can be treated to form metal and oxygen that can still be used as a catalyst for methane oxidation; the resulting oxygen can continue to be used as an oxidant. We also calculated the rate constant of methane oxidation reaction to give the resulting methanol pathway. The calculated dynamic characterisation shows that the rate constant has a positive temperature dependence. Our calculation show that this reaction is exothermic reaction via the RuO/RhO/PdO catalyst, and the reaction is thermodynamically feasible. This study also provides theoretical reference data for us to identify new catalysts for the catalytic oxidation of methane.