Facile reduction of nitrophenols: Comparative catalytic efficiency of MFe₂O₄ (M聽=聽Ni, Cu, Zn) nano ferrites

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• 作者：Ankita Goyal^a ; S. Bansal^b ; Sonal Singhal^a ; ^{sonal1174@gmail.com" class="auth_mail}
• 关键词：Nitrophenols ; Magnetic ferrites ; Kinetics and catalyst reduction
• 刊名：International Journal of Hydrogen Energy
• 出版年：26 March, 2014
• 年：2014
• 卷：39
• 期：10
• 页码：4895-4908
• 全文大小：2142 K

文摘

Nano ferrites of the formula MFe₂O₄ (M聽=聽Ni, Cu, Zn), synthesized using sol-gel technique, were employed to catalyze the reductive transformation of nitrophenols to aminophenols. The catalytic reduction was carried out in the excess of NaBH₄ as reducing agent in aqueous medium at room temperature. CuFe₂O₄ and NiFe₂O₄ were found to be active for the reduction of nitrophenols with significant difference in their activities whereas ZnFe₂O₄ was found to be inactive. The kinetics of the reduction of nitrophenols to aminophenols was also investigated. The reaction followed pseudo first order kinetics. The first order rate constant values for 30聽mol% of CuFe₂O₄ and NiFe₂O₄ for the reduction of 2-nitrophenol were observed to be 3.68聽min^鈭? and 0.33聽min^鈭? respectively. The rates of reduction for the three isomers of nitrophenol were also studied and were observed to follow the order - 2-nitrophenol聽>聽4-nitrophenol聽>聽3-nitrophenol. The selective formation of aminophenol was confirmed using LC-MS, ¹H NMR and FT-IR spectroscopic techniques.