Alumina-supported oxime for the degradation of sarin and diethylchlorophosphate

1-(4-Chlorophenyl))-N-hydroxymethanimine and cyclohexyl-N-hydroxymethanimine were synthesized and a well-established oxime, i.e., 2-[(hydroxyimino)methyl]-1-methylpyridinium chloride was purchased. Thereafter; all were loaded over Al2O3 using incipient wetness technique. The prepared systems were characterized using surface area analyzer, scanning electron microscope, energy dispersive X-ray spectrophotometer, Fourier transform infrared spectrophotometer and thermogravimetric analyzer. Kinetics of the degradation of sarin (GB) and simulant, i.e. diethylchlorophosphate (DEClP) was studied over synthesized oxime impregnated Al2O3 and results were compared with well reported oxime impregnated Al2O3. Kinetics of reaction was found to be following the pseudo first order reaction kinetics. The order of reactivity of the prepared systems was found to be cyclohexyl-N-hydroxymethanimine/Al2O3 > 1-(4-chlorophenyl)-N-hydroxymethanimine/Al2O3 > 2-[(hydroxyimino)methyl]-1-methylpyridinium chloride/Al2O3 > Al2O3. From the reaction kinetics it was observed that the reaction with DEClP was faster than with GB. Cyclohexyl-N-hydroxymethanimine/Al2O3 was found to be the most reactive system with half-life of 0.94 and 15 h for DEClP and GB respectively.

► Synthesized and procured oximes were loaded on Al2O3.
► Degradation Kinetics of GB and DEClP found to be following first order kinetics.
► Reactivity order: oxime-2/Al2O3 > oxime-1/Al2O3 > PAM chloride/Al2O3 > Al2O3.
► Reaction mechanism for the degradation of GB and DEClP was proposed.