DFT Analysis of the Adsorption of Methyl Nitrate on Al 2 O 3 Surfaces

The adsorption of the energetic molecule methyl nitrate ( CH 3 ONO 2 ) on α‐ Al 2 O 3 (0001) and γ‐ Al 2 O 3 (110) surfaces was investigated using first‐principles calculations based on density functional theory and the generalized gradient approximation. We found that CH 3 ONO 2 approaches the two surfaces by either the oxygen connected with carbon atom or an oxygen atom of the nitro group; however, the former interaction is more stable. If CH 3 ONO 2 approaches the surface through the oxygen atom of the nitro group, the adsorption is non‐dissociative; while it is nearly dissociative if CH 3 ONO 2 adsorbs on the surface via the oxygen connected with carbon atom and a surface tri‐coordinated Al atom. Moreover, the dissociation trend on the γ‐ Al 2 O 3 (110) surface is more pronounced. In addition, the adsorption of CH 3 ONO 2 on the γ‐ Al 2 O 3 (110) surface is more favorable. Finally, although strong interactions exist between CH 3 ONO 2 and the surfaces, the structures of the alumina films are not affected by the adsorption of CH 3 ONO 2 .