Study of Methane Dehydroaromatization on Impregnated Mo/ZSM-5 Catalysts and Characterization of Nanostructured Molybdenum Phases and Carbonaceous Deposits Full article
| Journal |
Industrial and Engineering Chemistry Research
ISSN: 0888-5885 , E-ISSN: 1520-5045 |
||||
|---|---|---|---|---|---|
| Output data | Year: 2007, Volume: 46, Number: 12, Pages: 4063-4074 Pages count : 12 DOI: 10.1021/ie0609564 | ||||
| Tags | Catalysts; Molybdenum; Nanostructured materials; X ray diffraction analysis | ||||
| Authors |
|
||||
| Affiliations |
|
Funding (1)
| 1 | Netherlands Organisation for Scientific Research | 047.15.012 |
Abstract:
Methane dehydroaromatization was studied over a series of impregnated Mo/ZSM-5 catalysts with different molybdenum contents and Si/Al atomic ratios in the parent H-ZSM-5 zeolites. The maximum catalytic activity (∼14% CH4 conversion) and benzene formation selectivity (∼70%) were observed for the samples with 2%−5% molybdenum. The activity and selectivity are improved when the Si/Al ratio is decreased from 45 to 17. After pretreatment in argon and reaction at 720 °C, the catalysts have been characterized by textural methods, X-ray diffractometry (XRD), differential thermal analysis (DTA), high-resolution transmission electron microscopy (HRTEM), and energy-dispersive X-ray spectroscopy (EDX). As determined by HRTEM, after the pretreatment, the MoOx phase is highly dispersed on the external surface of the zeolite. During the reaction, molybdenum carbide nanoparticles 2−15 nm in size are formed on the external surface, and the molybdenum-containing clusters are deposited in the zeolite channels. The carbonaceous deposits (CDs) are formed as graphite layers on the surface of Mo2C nanoparticles that were >2 nm in size, and as friable layers with a disordered structure on the external surface of the zeolite. According to EDX, XRD, and DTA studies, the content of the CD and the extent of their condensation (the C/H ratio) increase with the time-on-stream. For all the studied molybdenum contents (1%−10%) and time-on-stream values (0.5−6 h), the CDs formed on the catalysts with Si/Al = 17 are characterized by one maximum of the exothermic burn-out effect in DTA, whereas on the catalysts with Si/Al = 30 and 45, they are characterized by two such maxima. A correlation between the catalyst activity, the selectivity versus nanostructure, and the location of the molybdenum phases and CDs is discussed.
Cite:
Matus E.V.
, Ismagilov I.Z.
, Sukhova O.B.
, Zaikovskii V.I.
, Tsikoza L.T.
, Ismagilov Z.R.
, Moulijn J.A.
Study of Methane Dehydroaromatization on Impregnated Mo/ZSM-5 Catalysts and Characterization of Nanostructured Molybdenum Phases and Carbonaceous Deposits
Industrial and Engineering Chemistry Research. 2007. V.46. N12. P.4063-4074. DOI: 10.1021/ie0609564 WOS Scopus РИНЦ ANCAN OpenAlex
Study of Methane Dehydroaromatization on Impregnated Mo/ZSM-5 Catalysts and Characterization of Nanostructured Molybdenum Phases and Carbonaceous Deposits
Industrial and Engineering Chemistry Research. 2007. V.46. N12. P.4063-4074. DOI: 10.1021/ie0609564 WOS Scopus РИНЦ ANCAN OpenAlex
Dates:
| Published online: | Jun 12, 2006 |
| Submitted: | Jul 22, 2006 |
| Accepted: | Oct 20, 2006 |
| Published print: | Jun 1, 2007 |
Identifiers:
| Web of science: | WOS:000246803800022 |
| Scopus: | 2-s2.0-34250828435 |
| Elibrary: | 13550746 |
| Chemical Abstracts: | 2006:1269252 |
| Chemical Abstracts (print): | 146:464837 |
| OpenAlex: | W2088247876 |