Nanoscale Metal Oxide Particles as Chemical Reagents. Destructive Adsorption of aChemical Agent Simulant, Dimethyl Methylphosphonate, on Heat-Treated Magnesium Oxide

摘要

Nanoscale particles of MgO were prepared as fine powders of varied surface areasand crystallite sizes. The capacities of these samples for dissociative (destructive) adsorption of dimethyl methylphosphonate (DMMP), a chemical agent simulant, were determined by using a pulsed microreactor. Surface stoichiometric reactions were encountered and large amounts of DMMP were destroyed, about one DMMP molecule to two surface Mg0 moieties. Volatile products were formic acid and methanol. Elemental analyses of the spent MgO samples coupled with Fourier transform infrared photoacoustic spectroscopy indicated that the phosphorus-containing molecular fragment was immobilized as CH30PCH3ads. Effects of contact time, temperature, and surface area were studied. A proposed reaction scheme for the decomposition is given, which involved loss of CH30 followed by its oxidation by a second DMMP molecule.