کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6453704 | 1418802 | 2017 | 18 صفحه PDF | دانلود رایگان |
- Ceria, pristine perovskites and Ceria-perovskite composites LaMO3 (Cu, Fe) were prepared by the calcination, citric acid sol-gel and impregnation method, respectively.
- The synthesized structures were tested in CWPO of Bisphenol F.
- Higher activity and stability was observed for CeO2-LaCuO3 and CeO2-LaFeO3.
- Quenching reactions and EPR measurements were conducted to probe the reaction mechanism.
- CeO2-LaCuO3 was stable, reusable and active over a broad pH range.
In the present study, ceria, pristine perovskites LaMO3 (Cu, Fe) and novel ceria-perovskite composites CeO2-LaMO3 were successfully prepared and applied as heterogeneous Fenton like- catalysts for the degradation and mineralization of a new emergent compound- bisphenol F (BPF) in aqueous solution. The catalysts were characterized by X-ray diffraction spectrometer (XRD), BET surface area determination, scanning electron microscopy (SEM), Energy Dispersive X-ray (EDS) and X-ray photoelectron spectroscopy (XPS) techniques. Catalytic bisphenol F behavior shows that the activity of pristine perovskites was improved due to the introduction of cerium. Catalytic activity in terms of TOC removal followed the order of CeO2-LaCuO3Â >Â CeO2-LaFeO3Â >Â LaCuO3Â >Â LaFeO3Â >Â CeO2 with about 83, 79, 68, 64 and 28% respectively. Only the novel composite oxide CeO2-LaCuO3 was found to be effective for Bisphenol F degradation at neutral conditions. EPR analyses and scavenging experiments revealed that BPF was mainly decomposed by the attack of OH, especially the surface-bounded OH. BPF decay followed pseudo-first-order reaction kinetics. The absolute rate constant for BPF oxidation by OH was found to 2.09109Â Mâ1Â sâ1, as determined by the competition kinetic method. Six stable organics intermediates were observed and five of them were identified p-benzoquinone, hydroquinone, 4-hydroxybenzaldehyde and Bis (4-hyroxyphenyl) methanol. Subsequent attack of these intermediates by OH radicals led to the formation of short chain acids: malonic, succinic, acetic, formic and oxalic acids. On the basis of the analytical results for the intermediate products and the assumption that hydroxyls radicals are the major reactive species, a plausible pathway of BPF mineralization during the heterogeneous Fenton process was proposed. Furthermore, the CeO2-LaCuO3 composite exhibited excellent long-term stability in the heterogeneous Fenton-like process. These results suggested that the novel ceria perovskite material would be a promising candidate for practical wastewater treatment.
143
Journal: Applied Catalysis B: Environmental - Volume 218, 5 December 2017, Pages 119-136