Catalytic effect of lucunary heteropolyanion containing molybdenum and tungsten atoms on decolorization of direct blue 71

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• 作者：Masoumeh Tabatabaee  ; ;   ; ^{tabatabaee45m@yahoo.com} ; Maria Roozbeh ; Mandana Roozbeh
• 关键词：Degradation ; Homogenous catalyst ; Polyoxometalates ; Lucunary Keggin structure
• 刊名：Chinese Chemical Letters
• 出版年：2011
• 出版时间：December 2011
• 年：2011
• 卷：22
• 期：12
• 页码：1501-1504
• 全文大小：292 K

文摘

In this research, a lucunary Keggin structure, [PMo₂W₉O₃₉]^{7?/sup> was selected as an efficient homogenous catalyst for degradation of an azo dye (direct blue 71) and a simple method was developed for degradation of DB71. The method is based on the oxidation of azo dye in the presence of a lucunary Keggin form of polyoxometalates, K₇[PMo₂W₉O₃₉]¡¤19H₂O, as a homogenous catalyst at room temperature. The reaction is monitored spectrophotometrically by measuring the absorbance of dye at ¦Ë = 585 nm. Some parameters including concentration of catalyst, concentration of H₂O₂, pH and reaction time were investigated and optimized. Results show that K₇[PMo₂W₉O₃₉]¡¤19H₂O is more efficient in the presence of hydrogen peroxide. Degradation of dye in the presence of the catalyst and H₂O₂ could lead to the disappearance approximately 65 % of dye after 60 min. But degradation for the same experiment performed in the absence of catalyst or in the absence of H₂O₂ was 22 % or 5 % respectively. Approximately 87 % azo dyes has been eliminated after 90 min in the presence of catalyst, H₂O₂ and optimize conditions (0.6 g/L of K₇[PMo₂W₉O₃₉]¡¤19H₂O, 0.08 mol/L hydrogen peroxide and room temperature).}