Mesoporous manganese oxide for the degradation of organophosphates pesticides
2016
Šťastný, Martin | Štengl, Václav | Henych, Jiří | Tolasz, Jakub | Vomáčka, Petr | Ederer, Jakub
Manganese(IV) oxide used for degradation of toxic organophosphorus compounds was prepared by homogeneous hydrolysis of potassium permanganate (KMnO₄) with 2-chloroacetamide. The prepared sample was characterized by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, and nitrogen physisorption. The degradation efficiency was determined with parathion methyl (PM) as representative of organophosphate pesticides using high-performance liquid chromatography. For a comparison, the commercially obtained product and the two synthesized manganese(IV) oxides prepared by direct reaction of manganese(II) sulfate (MnSO₄·H₂O) and potassium permanganate (KMnO₄) and potassium permanganate (KMnO₄) with urea in aqueous solution were tested. The sample prepared by homogeneous hydrolysis of KMnO₄ with 2-chloroacetamide showed the highest degradation efficacy. The reaction half-time in non-polar organic solvent (n-heptane) was around 0.9 min with the degradation efficiency of about 90 % within 2 h. It was shown that comparative samples of manganese(IV) oxides were variously effective in decomposition of PM by cleavage of the P–O-aryl bond in the pesticide molecule. The degradation mechanism for PM on the MnO₂ surfaces was proposed.
显示更多 [+] 显示较少 [-]