Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
The effect of ultrasonic treatment on iron–chromium pillared bentonite synthesis and catalytic wet peroxide oxidation of phenol
Abstract In this study, compared to traditional methods, Fe/Cr-pillared bentonite synthesis whose Fe/Cr mol ratio is 1/9 is carried out by considerably reducing the water consumption and synthesis time. Fe/Cr-pillared bentonites were characterized by scanning electron microscope with energy dispersive system (SEM–EDS), powder X-ray diffraction (XRD) and N2-adsorption/desorption isotherm. The characterization results indicated that the Fe/Cr-DC sample prepared by adding dry clay to the pillaring solution directly exhibits comparable surface properties to those of the sample (Fe/Cr-SS) prepared by adding the pillaring solution on clay dispersion slowly. Catalytic behavior of Fe/Cr-pillared bentonites was tested for the catalytic wet peroxide oxidation (CWPO) of phenol with ultrasonic heating. No significant difference is observed among the phenol conversions for all of the synthesized samples. Phenol conversion increased with increasing temperature until 45°C, but further increasing the temperature in higher than 45°C was not very effective. The phenol conversion at pH5 was higher than at pH7. Additionally, a nearly complete removal of phenol was obtained over 2h using Fe/Cr-DC catalysts, at the experimental conditions of T=45°C, pH5, mcat =5g/L, [H2O2/phenol]=16, during reaction peroxide addition (2×10−4 mol/h) and ultrasonic heating. It is obtained that, aromatic intermediate products as catechol, hydroquinone and benzoquinones which are obtained in the beginning of oxidation oxidated into carboxylic acids. However, carboxylic acids such as oxalic and formic acid showing resistance to oxidation results by the level of total organic carbon (TOC) conversion being low.
Graphical abstract Display Omitted
Highlights Fe/Cr-pillared bentonites were prepared by considerably reducing the water consumption and synthesis time. Catalytic activities were tested for the catalytic wet peroxide oxidation of phenol with ultrasonic heating. Temperature was found to have a more pronounced effect, increasing the phenol conversion and mineralization. Aromatic and aliphatic oxidation intermediates are identified.
The effect of ultrasonic treatment on iron–chromium pillared bentonite synthesis and catalytic wet peroxide oxidation of phenol
Abstract In this study, compared to traditional methods, Fe/Cr-pillared bentonite synthesis whose Fe/Cr mol ratio is 1/9 is carried out by considerably reducing the water consumption and synthesis time. Fe/Cr-pillared bentonites were characterized by scanning electron microscope with energy dispersive system (SEM–EDS), powder X-ray diffraction (XRD) and N2-adsorption/desorption isotherm. The characterization results indicated that the Fe/Cr-DC sample prepared by adding dry clay to the pillaring solution directly exhibits comparable surface properties to those of the sample (Fe/Cr-SS) prepared by adding the pillaring solution on clay dispersion slowly. Catalytic behavior of Fe/Cr-pillared bentonites was tested for the catalytic wet peroxide oxidation (CWPO) of phenol with ultrasonic heating. No significant difference is observed among the phenol conversions for all of the synthesized samples. Phenol conversion increased with increasing temperature until 45°C, but further increasing the temperature in higher than 45°C was not very effective. The phenol conversion at pH5 was higher than at pH7. Additionally, a nearly complete removal of phenol was obtained over 2h using Fe/Cr-DC catalysts, at the experimental conditions of T=45°C, pH5, mcat =5g/L, [H2O2/phenol]=16, during reaction peroxide addition (2×10−4 mol/h) and ultrasonic heating. It is obtained that, aromatic intermediate products as catechol, hydroquinone and benzoquinones which are obtained in the beginning of oxidation oxidated into carboxylic acids. However, carboxylic acids such as oxalic and formic acid showing resistance to oxidation results by the level of total organic carbon (TOC) conversion being low.
Graphical abstract Display Omitted
Highlights Fe/Cr-pillared bentonites were prepared by considerably reducing the water consumption and synthesis time. Catalytic activities were tested for the catalytic wet peroxide oxidation of phenol with ultrasonic heating. Temperature was found to have a more pronounced effect, increasing the phenol conversion and mineralization. Aromatic and aliphatic oxidation intermediates are identified.
The effect of ultrasonic treatment on iron–chromium pillared bentonite synthesis and catalytic wet peroxide oxidation of phenol
Tomul, Fatma (Autor:in)
Applied Clay Science ; 120 ; 121-134
05.11.2015
14 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
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