Degradation of Methyl Paraoxon in the Presence of Mg²⁺-Al³⁺ Mixed Oxides

Abstract

Al 3+ -Mg 2+ mixed oxides were prepared by coprecipitation and characterized with scanning electron microscopy (SEM), energy dispersive Xray fluorescence (EDXRF), temperature programmed desorption of CO 2 (CO 2 -TPD), and N 2 adsorption/desorption isotherms (BET and BJH methods). By increasing the MgO concentration up to 31.8% (w/w), X-ray diffraction (XRD) measurements suggested an incipient magnesium aluminate spinel (MgAl 2 O 4 ) phase. However, the spinel crystalline structure was obtained only after calcination at 950 °C. These materials were tested as catalysts in the propanolysis reaction of methyl paraoxon. This reaction in the presence of the more efficient incipient MgAl 2 O 4 spinel is of the order of 2.5 × 10 5 -fold faster than the spontaneous propanolysis reaction and results in the formation of a product that is structurally related to a family of flame retardants. The different products of propanolysis and hydrolysis were identified by electrospray ionization mass spectrometry (ESI(+)-MS), ESI(+)-MS/MS) and liquid chromatography mass spectrometry (LC-MS/MS).

From DNA to Nerve Agents – The Biomimetic Catalysts for the Hydrolysis of Phosphate Esters

“…It was concluded that most of the phosphorus compounds react with Al 2 O 3 to form AlPO 4 . Nome et al tested the Mg 2+ covered Al 2 O 3 in aqueous solution in the hydrolysis of phosphate diester ethyl 2,4‐dinitrophenyl phosphate (DEDNPP). Using coprecipitation method, they obtained Mg 2+ ‐Al 3+ mixed oxides and then examined their catalytic efficiency in hydrolyzing methyl paraoxon.…”

“…Because of the chemical stability of P−O bonds, the decomposition of organophosphorus compounds remains a challenging problem . It would be helpful to develop the non‐enzyme catalysts which can destroy the large stockpiles of such compounds.…”

Non-photochemical catalytic hydrolysis of methyl parathion using core–shell Ag@TiO2 nanoparticles

“…Previous authors have proposed a similar mechanism to explain the hydrolysis mechanism of a variety of organophosphates and organic transformations in the presence of TiO 2 based materials or other metal oxides. 7,29,34,35 Our proposed mechanism is shown in Fig. 6.…”

Synthesis of high-surface-area spinel-type MgAl 2 O 4 nanoparticles by [Al(sal) 2 (H 2 O) 2 ] 2 [Mg(dipic) 2 ] and [Mg(H 2 O) 6 ][Al(ox) 2 (H 2 O) 2 ] 2 ⋅5H 2 O: influence of inorganic precursor type

“…XRD presented in figure 11. All the curves can be considered as a type IV isotherm, typical of mesoporous materials [25].…”