Trotte Natália S F, Alzamora M, Sánchez D R, Carvalho Nakédia M F
a Instituto de Química, Universidade do Estado do Rio de Janeiro , Rio de Janeiro , Brazil.
b Universidade Federal do Rio de Janeiro , Duque de Caxias , Brasil.
Environ Technol. 2018 Nov;39(21):2822-2833. doi: 10.1080/09593330.2017.1367038. Epub 2017 Aug 29.
This study aims to prepare environmentally friendly iron catalysts supported on silica, using glycerol as green reducing and stabilizing agent, for application in heterogeneous Fenton degradation of the pollutant dye methyl orange (MO). The catalysts were characterized by X-ray powder diffraction, atomic absorption spectroscopy, scanning electron microscopy, transmission electron microscopy, thermogravimetric analyses, Mössbauer and Fourier transform infrared spectroscopies, which revealed the formation of iron(II)/(III) oxalates from the oxidation of glycerol by the iron(III) nitrate precursor. Besides, iron oxihydroxide nanoparticles with superparamagnetic behavior were also formed. Iron catalysts prepared in the presence of nickel(II) or zinc(II) nitrates lead to the formation of the corresponding oxalates. The catalysts were able to degrade MO, efficiently in 180 min of reaction. Fe/SiO furnished higher reaction rates, followed by Zn4Fe2/SiO, which presented higher iron content as well as the smallest nanoparticles. Reaction parameters such as catalyst dosage, hydrogen peroxide concentration, pH and reaction temperature were investigated.
本研究旨在制备负载在二氧化硅上的环境友好型铁催化剂，使用甘油作为绿色还原剂和稳定剂，用于污染物染料甲基橙（MO）的非均相芬顿降解。通过X射线粉末衍射、原子吸收光谱、扫描电子显微镜、透射电子显微镜、热重分析、穆斯堡尔谱和傅里叶变换红外光谱对催化剂进行了表征，结果表明硝酸铁前驱体氧化甘油形成了草酸铁（II）/（III）。此外，还形成了具有超顺磁行为的氢氧化铁纳米颗粒。在硝酸镍（II）或硝酸锌（II）存在下制备的铁催化剂会导致相应草酸盐的形成。这些催化剂能够在180分钟的反应中有效降解MO。Fe/SiO具有更高的反应速率，其次是Zn4Fe2/SiO，其铁含量更高且纳米颗粒最小。研究了催化剂用量、过氧化氢浓度、pH值和反应温度等反应参数。
