XAFS Study on Re/Zeolite Catalysts for Direct Phenol Synthesis from Benzene with Molecular Oxygen
نویسندگان
چکیده
Introduction Phenol is an important chemical in industry but has been produced from benzene by the three-steps of cumene process. Direct phenol synthesis from benzene is one of the important subjects. However, no selective catalyst with good performance in an economically and environmentally favourable benzene-O2 system has been discovered to date. We have found Re/HZSM-5 promoted the direct phenol synthesis from benzene with 88% (steady-state) and 94% (pulse) selectivity using molecular oxygen as an oxidant under co-existing NH3.
منابع مشابه
Stable Fe/ZSM-5 Nanosheet Zeolite Catalysts for the Oxidation of Benzene to Phenol
Fe/ZSM-5 nanosheet zeolites of varying thickness were synthesized with di- and tetraquaternary ammonium structure directing agents and extensively characterized for their textural, structural, and catalytic properties. Introduction of Fe3+ ions in the framework of nanosheet zeolites was slightly less effective than in bulk ZSM-5 zeolite. Steaming was necessary to activate all catalysts for N2O ...
متن کاملCa-modified MFI zeolite: A study on its synthesis, characterization and catalytic activity
Using hydrothermal synthesis process a series of Mobil Five (MFI) zeolites were synthesized with silica to alumina ratio (SAR) of 50, 100 and 200. The synthesized MFI zeolites were used to exchange with 0.5%, 1.0% and 2.0% Ca(NO3)2 solutions for modification of MFI zeolites to Ca-MFI zeolite. The formation of MFI zeolite phases was identified by XRD and FT-IR analysis. TGA...
متن کاملA hierarchical Fe/ZSM-5 zeolite with superior catalytic performance for benzene hydroxylation to phenol.
We report the one-step synthesis of a highly active hierarchical Fe/ZSM-5 zeolite catalyst with a strongly improved lifetime in the selective hydroxylation of benzene to phenol with nitrous oxide; compared to the best Fe/ZSM-5 catalyst, the turnover number after 24 h on stream is almost four times higher.
متن کاملA Computational Study on the Aerobic Oxidation of Benzene to Phenol in Cu/Exchanged Y Zeolite
In heterogeneous catalysis transition metal-containing zeolites, in particular copperexchanged zeolites, have been studied experimentally [1, 2] as well as theoretically. Zeolites have large surface areas and different active sites (Brønsted acid sites and transition metal centers) which play a significant role in catalysis. In order to study the catalytic oxidation of benzene to phenol using d...
متن کاملMössbauer and Magnetic Studies of Iron-Zeolite and Iron-Cobalt Zeolite Catalysts Used in Synthesis Gas Conversion
Medium-pore (diameter ~ 6A) zeolites such as ZSM-5 and silicalite impregnated with Group VIII metals provide selective catalytic pathways for the conversion of synthesis gas to gasoline or olefins. Mössbauer and magnetic studies on these catalysts containing iron or iron plus cobalt are reported. The zeolites were impregnated with metal nitrate solutions, reduced, and carbided to yield showed F...
متن کامل