High-Temperature Decomposition of Diisopropyl Methylphosphonate on Alumina: Mechanistic Predictions from Ab Initio Molecular Dynamics

The enhanced degradation of organophosphorous-based chemical warfare agents (CWAs) on metal-oxide surfaces holds immense promise for neutralization efforts; however, the underlying mechanisms in this process remain poorly understood. We utilize large-scale quantum calculations first time to probe high-temperature diisopropyl methylphosphonate (DIMP), a nerve agent simulant. Our Born-Oppenheimer molecular dynamics (BOMD) show that $\gamma$-Al$_2$O$_3$ surface shows quickly adsorbing and destroying CWAs. find alumina adsorbs DIMP at all temperatures, subsequent decomposition proceeds via propene elimination. BOMD are complemented with metadynamics simulations produce free energy paths, which activation barrier decreases temperature readily decomposes $\gamma$-Al$_2$O$_3$. first-principle provide crucial diagnostics sarin models mechanistic information examining CWA reactions other candidate metal oxide surfaces.