Thermal degradation of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) over synthesized Fe–Al composite oxide

Abstract

h i g h l i g h t sFeeAl composite oxide materials for BDE-47 degradation were successfully synthesized. Component and morphology of material were controlled by concentration of urea. Distribution of hydrodebromination products are analyzed over different material. Morphology and component might affect degradation pathway. a r t i c l e i n f o a b s t r a c tA series of FeeAl composite oxides were synthesized by the hydrothermal method using different urea dosages and examined towards the degradation of 2,2 0 ,4,4 0 -tetrabromodiphenyl ether (BDE-47) at 300 C. The as-prepared oxides were characterized by field-emission scanning electron microscopy, X-ray diffraction and energy-dispersive X-ray spectroscopy. The morphology and composition of the prepared materials could be regulated by controlling the urea concentration. Interestingly, these properties influenced the nature and amount of the hydrodebromination products generated during the degradation of BDE-47. The degradation of BDE-47 over the composite oxide prepared at a urea dosage of 3 mmol generated BDE-17 as the major isomer product, followed by BDE-28/33, -30, and -32, among the tribromodiphenyl ethers (tri-BDEs). Regarding the dibromodiphenyl ethers (di-BDEs) produced, the amount of the isomers decreased in the order of BDE-8/11 > BDE-7 > BDE-15 > BDE-10. And the BDE-1 among monobromodiphenyl was determined. In contrast, over the composite oxides prepared at urea dosages greater than 3 mmol, BDE-28/33 gradually become the major isomer product instead of BDE-17 among tri-BDEs. The amount of the other di-BDEs isomer such as BDE-15 and -10 approach to be comparable to that BDE-8/11. However, regardless of the urea dosage, BDE-47 converted into BDE-75 via an isomerization reaction. Based on these intermediate products identification, a possible hydrodebromination mechanism of BDE-47 over FeeAl composite oxide was comprehensively traced.

Synthesis of three crystalline forms of Al2O3 featuring rod-like fibers and their effect on the gaseous degradation of 1-chloronaphthalene

“…12,13 Furthermore, Yang et al showed that high degradation efficiencies for 2,2′,4,4′-tetrabromodiphenyl ether of above 92% could be attained over Fe-Al composite oxides prepared with different urea dosages. 14 Jia et al reported a HCB degradation efficiency of 99.9% over a Fe x O y -CeO 2 composite at 300°C. 10 It is known that the crystal form of a material, which relates to the physical and chemical properties of the material, influences the catalytic performance of the material.…”

“…20 Previous research studies have pointed out that Al 2 O 3 has important applications as a catalyst and/or a high-surface catalyst support for eliminating organic pollutants. 14,21,22 However, reports on the effects of different crystal forms of Al 2 O 3 on the catalytic activity of newly listed PCNs are particularly scarce. Investigating the relationship between the different crystalline forms of Al 2 O 3 and the catalytic activity toward PCN degradation is important to clarify the factors influencing the catalytic properties of Al 2 O 3 and elucidate the degradation mechanism.…”

Thermal Oxidation Degradation of 2,2′,4,4′-Tetrabromodiphenyl Ether over LiαTiOxMicro/Nanostructures with Dozens of Oxidative Product Analyses and Reaction Mechanisms

“…Potential methods for PBDE removal in contaminated environmental systems have been reported, with a strong focus on reductive debromination. Yang et al 9 reported that BDE-47 could undergo reductive debromination to mono-totri-BDEs over Fe−Al composite oxide. Keum and Qing 10 showed that zerovalent iron is more effective for the reductive degradation of decabromodiphenyl ether (BDE-209).…”

Degradation of one-side fully-chlorinated 1,2,3,4-tetrachloronaphthalene over Fe–Al composite oxides and its hypothesized reaction mechanism

“…Similar changes have also been reported in the XRD patterns of mesoporous iron-based spinels and synthetic Fe-Al composite oxides. 33,34 Table 1 provides a summary of the parameters used for the BET experiments involving the three different Fe-Al composites. The results revealed that FeAl-10 had the largest surface area at 108 m 2 g À1 , followed sequentially by FeAl-5 and FeAl-1, which had surface areas of 98 and 89 m 2 g À1 , respectively.…”