Abstract
The kinetics of the destruction of diisopropyl methylphosphonate (DIMP) in corona discharge has been studied using a flow tubular coaxial wire dielectric barrier corona discharge reactor. The identification and quantitative determination of DIMP, its destruction intermediates, and phosphorusβcontaining destruction products were performed using molecular beam mass spectrometry and gas chromatography/mass spectrometry. Active discharge power was varied in the range 0.01β5 W. The destruction products such as isopropyl methylphosphonate, methylphosphonic acid, and orthophosphoric acid were found on the reactor walls. The dependence of the extent of the destruction, D (D = 1 β X / X~0~, where X and X~0~ are DIMP mole fractions at the outlet and the inlet of the reactor), on the specific energy deposition E~x~ (E~x~ = PF^β1^ X~0~^β1^, where F is the carrier gas flow and P is the power dissipated in discharge reactor) was measured over the DIMP mole fraction range 60β500 ppm at the pressure of 1 bar and the temperature of 340 K. Over the range of the experimental conditions studied the destruction obeys the βpseudoβfirstβorderβ kinetic law: ln(1 β D) = βKE~x~. Plausible mechanisms of the destruction are discussed. It was concluded that ion mechanism is the major one responsible for the destruction process. Β© 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 331β337, 2002