Reactive interaction between powders generated by aluminum combustion and diisopropyl methyl phosphonate

Illegal stockpiles of organophosphorus chemical warfare agents (CWAs) continue to exist and pose danger. Their destruction can involve combustion of energetic formulations, commonly including aluminum powder as a fuel. Understanding how the generated combustion products affect the breakdown of CWA molecules is imperative to ensure that no toxic compounds are released in the environment. Relevant laboratory experiments often use diisopropyl methyl phosphonate (DIMP) as a low-toxicity CWA surrogate. Here, it is investigated how condensed combustion products of aluminum adsorb and decompose both liquid and vapor-phase DIMP. Aluminum powders with different morphologies are prepared and burned in an O 2 /N 2 -filled vessel. The resulting product powders are exposed to DIMP vapor in a flow reactor at 200 °C. Separately, the products are exposed to liquid DIMP. The combustion product powders exposed to either liquid or vapor phase DIMP are subsequently heated in a thermal analyzer up to 350 °C to measure the residual mass left on their surfaces. The residues are also characterized using FTIR. The results are compared to earlier experiments with commercial γ-Al 2 O 3 . DIMP vapors decomposed more effectively when interacting with the combustion products containing more δ−Al 2 O 3 . The mass of surface residues scaled inversely with the material's capacity to decompose DIMP.