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Zhang, Chunlei; Li, Shuang; Yuan, Yang; Zhang, Wenxiang; Wu, Tonghao; Lin, Liwu

doi:10.1023/a:1019046104593

Cited by 143 publications

(52 citation statements)

References 15 publications

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“…A Porapak Q packed column (3 mm × 2 m) connected to a thermal conductivity detector and a methylsilicone HP-1 capillary column (0.32 mm × 50 m) connected to a flame-ionization detector (FID) were used to separate and detect all reaction products. The first column was used to measure H 2 , Ar, CH 4 , CO, and CO 2 , and the second column to measure CH 4 , C 2 H 4 , C 2 H 6 , benzene, toluene, and naphthalene. Small amounts of other hydrocarbons were also detected in the capillary column; these included C 3 , C 4 , and C 5 alkanes, xylenes, and methylnaphthalenes.…”

Section: Catalytic Conversion Of Methanementioning

confidence: 99%

“…[11][12][13][14] The catalyst operates as a bifunctional catalyst for methane conversion to aromatics. 5 The similarities between Mo and W, and between Mo 2 C and WC, in their catalytic properties suggest that W/H-ZSM5 materials should resemble Mo/H-ZSM5 in their ability to activate CH 4 . 15 Yet, recent studies have concluded that Mo/H-ZSM5 catalysts are significantly more active and selective than W/H-ZSM5 in methane conversion reactions.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Synthesis, Structural Characterization, and Catalytic Properties of Tungsten-Exchanged H-ZSM5

et al. 2001

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W-exchanged H-ZSM5 was prepared by sublimation of WCl 6 at 673 K followed by hydrolysis of exchanged WCl x species at 523 K. D 2 exchange with residual OH groups showed that each W initially replaced about two zeolitic protons for W/Al ratios of 0.29 and 0.44, consistent with the formation of (WO 2 ) 2+ containing W 6+ species bridging two cation exchange sites. As temperatures reached ∼973 K during D 2 -OH exchange, these species reduced to (WO 2 ) + with the concurrent formation of one OD group. CH 4 conversion turnover rates (per W) and C 2 -C 12 selectivities are very similar to those observed on a Mo/H-ZSM5 sample with similar cation exchange level. As in the case of Mo/H-ZSM5, WO x /H-ZSM5 precursors are initially inactive in CH 4 reactions, but they activate during induction with the concurrent evolution of CO, H 2 O, and an excess amount of H 2 . The reduction and carburization processes occurring during CH 4 reactions and the structure of the exchanged WO x precursors was probed using in situ X-ray absorption spectroscopy (XAS). XAS studies confirmed the isolated initial nature of the exchanged WO x precursors after hydrolysis and dehydration and the formation of WC x clusters ∼0.6 nm in diameter during CH 4 reactions at 973 K. The structural and catalytic resemblance between W-and Mo-exchanged H-ZSM5 is not unexpected, in view of chemical similarities between oxides or carbides of Mo and W. The synthesis of exchanged WO x precursors and their subsequent carburization during CH 4 reactions, however, are more difficult than the corresponding processes for the MoO x counterparts. This may account for previous reports of lower CH 4 reaction rates and aromatics selectivities on W/H-ZSM5 compared with those observed on Mo/H-ZSM5 and with those reported here for rigorously exchanged W/H-ZSM5.

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Section: Catalytic Conversion Of Methanementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Synthesis, Structural Characterization, and Catalytic Properties of Tungsten-Exchanged H-ZSM5

et al. 2001

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“…Recently, methane dehydro-aromatization (MDA) has received much attention in the catalytic cycle around the world [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Many researchers claimed that Mo/HZSM-5, prepared by impregnation and/or solid-state reaction methods is the best catalyst [8,9].…”

Section: Introductionmentioning

confidence: 99%

The chemical nature of carbonaceous deposits and their role in methane dehydro-aromatization on Mo/MCM-22 catalysts

Wang

et al. 2002

Applied Catalysis A: General

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“…Many researchers have evaluated a number of HZSM-5 catalysts modified with various transition metal ions (TMI) [4], as well as molybdenum-containing compounds supported on various oxides and zeolites [5][6][7][8]. After studying catalysts with different Mo loading and prepared by different methods, researchers have found that catalysts having Mo loading of 2-6% and HZSM-5 with SiO 2 /Al 2 O 3 ratio of about 30-50 [9] showed good catalytic performances.…”

Section: Introductionmentioning

confidence: 99%

Study of the carbonaceous deposits formed on a Mo/HZSM-5 catalyst in methane dehydro-aromatization by using TG and temperature-programmed techniques

Tian

et al. 2001

Applied Catalysis A: General

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Untitled

Cited by 143 publications

References 15 publications

Synthesis, Structural Characterization, and Catalytic Properties of Tungsten-Exchanged H-ZSM5

Synthesis, Structural Characterization, and Catalytic Properties of Tungsten-Exchanged H-ZSM5

The chemical nature of carbonaceous deposits and their role in methane dehydro-aromatization on Mo/MCM-22 catalysts

Study of the carbonaceous deposits formed on a Mo/HZSM-5 catalyst in methane dehydro-aromatization by using TG and temperature-programmed techniques

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