Degradation of phenol via wet-air oxidation over CuO/CeO₂–ZrO₂nanocatalyst synthesized employing ultrasound energy: physicochemical characterization and catalytic performance

Abstract

Catalytic wet air oxidation (CWAO) of phenol was carried out under atmospheric pressure of oxygen at 160 degrees C in a stirred batch reactor over copper catalysts supported by CeO2-ZrO2. The copper with different loadings were impregnated over the composite support by a sonication process. The catalysts were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDX), Brunauer-Emmett-Teller (BET) specific surface area and Fourier-transformed infrared analyses. Characteristic peaks attributed to copper were not found in XRD patterns even at high loadings, but based on EDX results, the existence of copper particles was confirmed. It means that sonochemical synthesis method even at high loadings produced small copper particles with low crystallinity and excellent dispersion over the CeO2-ZrO2 composite. FESEM micrographs indicated just slight enhancement in particle size at high loadings of Cu. Blank CWAO experiments illustrated low conversion of phenol using bare CeO2-ZrO2 support. Although some agglomeration of particles was found at high loadings of copper but owning to the fact that almost all ZrO2 particles incorporated into the CeO2 lattice at high contents of Cu, catalyst activity not only did not decrease but also the phenol conversion reached to the higher values. The optimal catalyst loading for phenol degradation was found to be 9 g/l. Complete conversion of phenol was achieved using CuO/CeO2-ZrO2 in 9 g/l catalyst loading with initial phenol concentration of 1000 ppm after 3 h of reaction.

Catalytic Liquid-Phase Oxidation of Phenolic Compounds Using Ceria-Zirconia Based Catalysts

“…In the case of MnO x /Ce 0.65 Zr 0.35 O 2 , while the high conversion of phenol (94%) was obtained, phenol was mainly converted to carbonaceous deposits on the surface of the catalyst, which caused the deactivation. The high activity for the CuO supported on CeO 2 -ZrO 2 was also reported by Parvas et al (2014b), while Ni/CeO 2 -ZrO 2 showed low activity (Parvas et al, 2014a). …”

Abatement of toluene from polluted air over Mn/Clinoptilolite–CeO2 nanopowder: Impregnation vs. ultrasound assisted synthesis with various Mn-loading

“…A comparison between FTIR spectra of these samples reveals no noticeable changes. However, the stretching vibration for structural -OH and absorbed water at wave number of 3450 and 1640 cm À1 for all the samples were noticed these vibrations refer to physically absorbed water on all samples after catalyst heat treatment [52][53][54]. The main characteristic bands of clinoptilolite were found at wavelength of 460, 600, 725, and 1075 cm À1 .…”

The beneficial utilization of natural zeolite in preparation of Cr/clinoptilolite nanocatalyst used in CO2-oxidative dehydrogenation of ethane to ethylene

“…The peak observed at 2360 cm À1 may be 538 attributed to the asymmetric stretching frequency [y(CO)] of CO 2 539 [66][67][68]. It is caused due to the aerial CO 2 [64].…”