Catalytic Efficiency of Cu-Supported Pyrophyllite in Heterogeneous Catalytic Oxidation of Phenol

• Published in: Arabian journal for science and engineering (2011) Vol. 44; no. 7; pp. 6313 - 6325
• Main Authors: El Gaidoumi, A., Doña-Rodríguez, J. M., Pulido Melián, E., González-Díaz, O. M., Navío, J. A., El Bali, B., Kherbeche, A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-07-2019; Springer Nature B.V
• Subjects: Bacteria; Bioluminescence; Catalysis; Catalysts; Catalytic oxidation; Clay minerals; Copper; Degradation; Engineering; Fourier transforms; Humanities and Social Sciences; Hydrogen peroxide; Leaching; multidisciplinary; Oxidation; Phenols; Photoelectrons; Pyrophyllite; Research Article - Chemistry; Science; Spectrum analysis; Toxicity; Transmission electron microscopy; X-ray diffraction; X-ray fluorescence; Heterogeneous catalysis; Phenol; Copper; Impregnated pyrophyllite; Catalyst
• ISSN: 2193-567X; 1319-8025; 2191-4281
• DOI: 10.1007/s13369-019-03757-2

The copper-impregnated pyrophyllite (Cu/RC) was prepared and used as catalyst in catalytic wet peroxide oxidation (CWPO) of phenol. The catalyst was prepared by impregnation of copper (2.5 wt%) into pyrophyllite-type clay and characterized by X-ray diffraction, X-ray fluorescence, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and transmission electron microscopy. The optimum operation conditions for CWPO of phenol over Cu/RC were determined by investigating the effects of pH, temperature, catalyst amount, and hydrogen peroxide concentration. Stability of the Cu/RC catalyst and toxicity of treated solution were studied, by measuring the copper concentration leached out from the catalyst and the inhibition of
Vibrio fischeri
bacteria bioluminescence, respectively. The probable degradation mechanism of phenol over Cu/RC was considered by HPLC analysis. The obtained results showed that Cu/RC achieved highest activity (total phenol degradation and 80% TOC reduction) and detoxification with remarkable low copper leaching concentration (0.006 
mg
L
-
1
)
at optimized conditions (pH
=
3,
T
=
50
∘
C, 2 
g
L
-
1
catalyst amount, 50 mg 
L
-
1
phenol concentration and 7.45 
mmol
L
-
1
hydrogen peroxide concentration during 4 h). Meanwhile, few intermediates with low concentration were observed by the HPLC analysis for the CWPO of phenol. The Cu/RC catalyst showed a good activity after five successive runs (88% of degradation and 73% mineralization) at optimized conditions.