Revealing the correlation between adsorption energy and activation energy to predict the catalytic activity of metal oxides for HMX using DFT

Abstract

Traditional selection of combustion catalysis is time-consuming and labor-intensive. Theoretical calculation is expected to resolve this problem. The adsorption energy of HMX and O atoms on 13 metal oxides was calculated using DMol3, since HMX and O are key substances in decomposition process. And the relationship between the adsorption energy of HMX, O on metal oxides (TiO2, Al2O3, PbO, CuO, Fe2O3, Co3O4, Bi2O3, NiO) and experimental T30 values (time required for the decomposition depth of HMX to reach 30%) was depicted as volcano plot. Thus, the T30 values of other metal oxides was predicted based on their adsorption energy on volcano plot and validated by previous experimental data. Further, the adsorption energy of HMX on ZrO2 and MnO2 was predicted based on the linear relationship between surface energy and adsorption energy, and T30 values were estimated based on volcano plot. The apparent activation energy data of HMX/MgO, HMX/SnO2, HMX/ZrO2, and HMX/MnO2 obtained from DSC experiments are basically consistent with our predicted T30 values, indicating that it is feasible to predict the catalytic activity based on the adsorption calculation, and it is expected that these simple structural properties can predict adsorption energy to reduce the large quantities of computation and experiment cost.

Keywords

• Density functional theory
• HMX
• Metal oxides
• Adsorption energy
• Activation energy