标题:
Catalytic oxygenation of dibenzothiophenes to sulfones based on Fe-III porphyrin complex
点击次数:
论文类型:
期刊论文
发表刊物:
APPLIED CATALYSIS A-GENERAL
收录刊物:
SCIE、EI
卷号:
396
期号:
1-2
页面范围:
101-106
ISSN号:
0926-860X
关键字:
Iron tetra-(2-chlorophenyl) porphyrin chloride; Oxygenation;
Dibenzothiophene
摘要:
Fe-III porphyrin complexes as biomimetic catalysts display remarkable activity in the oxidation of dibenzothiophenes (DBTs) to the corresponding sulfones, in the absence of co-reductants or sacrificial agents, for deep desulfurization. The influence of the reaction conditions on the catalytic oxygenation was investigated. UV-vis spectra of Fe-III porphyrin complexes under various reaction conditions revealed that temperature was a vital factor for the catalyst's lifetime. However, catalyst decomposition was not caused by thermal self-destruction but by oxygenation at high temperatures. The Fe-III porphyrin complex was decomposed partly during the oxygenation, which was retarded by adding carbazole (CAR) to the reaction medium. Fe-III porphyrins, substituted with electron-withdrawing groups (-Cl), showed higher efficiency than electron-donating groups (-OH). Radical scavenging experiments demonstrated that the oxygenation catalyzed by the Fe-III porphyrin complex was not a free-radical reaction. Based upon the DBTs' concentrations, obtained by gas chromatography, the catalytic oxygenation can be treated kinetically as a first-order reaction. Finally, a mechanism involving a two-step nucleophilic addition was proposed for the oxygenation. (C) 2011 Elsevier B.V. All rights reserved.
发表时间:
2011-04-15