Characterization of Re-Mo/ZSM-5 catalysts: How Re improves the performance of Mo in the methane dehydroaromatization reaction

López-Martín, Ángeles; Sini, Maria Franca; Cutrufello, Maria Giorgia; Caballero, A.; Colón, G.

doi:10.1016/j.apcatb.2021.120960

Cited by 14 publications

(22 citation statements)

References 26 publications

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“…It can be observed that when moving from N-Mo-HMCM-49 to C-Mo-HMCM-49, the reducibility of initial MoO 3 to MoO 2 in N-Mo-HMCM-49 catalyst increases, which can be considered to be due to the change in the anchoring sites of MoO 3 species inside the HMCM-49 channels with respect to different kinds of MoO 3 loading. Lower reducibility over N-Mo-HMCM-49 can be observed, which is due to the strong interaction of MoO x species with HMCM-49 [ 2 ]. Therefore, the variation in the reducibility of MoO x species, as shown in the H 2 -TPR analysis, verifies that the MoO 3 species change in the HMCM-49 zeolite significantly influences the binding of MoO x species.…”

Section: Resultsmentioning

confidence: 99%

“…Consequently, there is a need to explore an efficient method for methane conversion into value-added chemicals from the perspective of methane utilization and environmental friendliness. MDA is one of the most attractive reactions, because the products are high-value petrochemicals (benzene, toluene and xylene) that can be applied to produce industrial raw materials [ 2 ].…”

Section: Introductionmentioning

confidence: 99%

“…It is generally believed that the dispersion of metal Mo species in zeolite plays an important role in catalyst stability [ 7 ]. Many strategies have revealed improvements, including the addition of accelerators [ 2 , 8 , 9 ], modulation of the pH value of the impregnation solution [ 10 ], and modification of the zeolite surface by desilication/dealumination or silicification [ 11 ] to enhance the dispersity of Mo species. Furthermore, many alternative zeolitic structures have been developed and investigated with the aim of reducing carbon deposition at the active site in methane non-oxidative aromatization.…”

Section: Introductionmentioning

confidence: 99%

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MoO3 Nanobelt-Modified HMCM-49 Zeolite with Enhanced Dispersion of Mo Species and Catalytic Performance for Methane Dehydro-Aromatization

et al. 2022

Molecules

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The methane dehydro-aromatization reaction (MDA) is a promising methane valorization process due to the conversion of methane to value-added aromatics (benzene, toluene and naphthalene). However, one of the major disadvantages of utilizing zeolite in MDA is that the catalyst is rapidly inactivated due to coke formation, which eventually causes the activity and aromatic selectivity to decrease. Consequently, the process is not conducive to large-scale industrial applications. The reasonable control of Mo site distribution on the zeolite surface is the key factor for partially inhibiting the coking of the catalyst and improving stability. Here, MoO3 nanobelts can be used for alternative Mo precursors to prepare MDA catalysts. Catalysts modified with MoO3 nanobelts present higher activity (13.4%) and benzene yield (9.2%) than those catalysts loaded with commercial MoO3.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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MoO3 Nanobelt-Modified HMCM-49 Zeolite with Enhanced Dispersion of Mo Species and Catalytic Performance for Methane Dehydro-Aromatization

et al. 2022

Molecules

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“…In the current review we summarize the best results obtained with different catalysts reported during the last 25 years: methane conversion, C 2 products, and benzene yields, as well as the operating conditions (Figure and Table ). ,,− ,,,− As can be seen from Table , the Mo/HZSM-5 is the most investigated catalyst for the MDA reaction since the very first report in 1993 . Usually, the MDA reaction is carried out at temperatures from 650 to 800 °C, leading to an average benzene selectivity of 70%. ,,− Other catalysts for the MDA with lower performance including Fe/HZSM-5, GaN/SBA-15, TaH/SiO 2 , and bimetallic Pt-X/HZSM-5 have been reported.…”

Section: Methane Dehydroaromatization (Mda)mentioning

confidence: 99%

“… a Bold: monometallic catalysts used as references for the catalyst series; 1 benzene produced (%) is calculated by integration of a range of T.O.S specified for each case. Refs ,− ,,,,− . …”

Section: Methane Dehydroaromatization (Mda)mentioning

confidence: 99%

Catalytic Routes for Direct Methane Conversion to Hydrocarbons and Hydrogen: Current State and Opportunities

et al. 2022

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Natural gas, the cleanest fossil fuel, is an abundant source of methane and expected to play an increasingly important role in powering the world’s economic growth over the energy transition of the coming decades. Methane has the potential to be a CO2-free feedstock to cogenerate hydrogen (H2) and added value “building-blocks” chemicals (e.g., olefins and aromatics) for petrochemistry. In this review, the two processes (i) the oxidative coupling of methane (OCM) for production of ethylene and (ii) the nonoxidative methane dehydroaromatization (MDA) producing hydrogen and benzene are discussed. Both routes convert methane directly into valuable products, an advantage over the several-steps syngas route. The performances of various a variety of catalysts reported during the last 25 years for OCM (MnNaW, La2O3, Li-MgO, etc.) and MDA (M/HZSM-5, M/TNU-9, M/IM-5, M/ITQ-2, M@SiO2, M@CeO2, TaH/SiO2, GaN/SBA15, single-site M@HZSM-5, bimetallic M-M′/HZSM-5, core–shell structures, M/Zr(SO4)2 with M = Mo, Fe, Pt) under similar reaction conditions are compared. The major drawbacks and the strategies used to mitigate the main challenges related with the performance of the catalysts in both OCM and MDA reactions are critically revealed. For instance, the overoxidation in the OCM is mitigated by optimizing of the operating conditions, using alternative oxidants, and the application of membrane reactor technology are discussed. In the MDA reaction, the major issue is the catalyst deactivation by coke formation and migration and sintering of metallic active phases. Strategies for robust catalysts, methods for mild coke removal, pretreatment under reductive atmosphere are presented. Approaches to improve aromatics yields over coke production by addition of promoters or co-feed reactants to the MDA catalysts are also discussed.

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Catalytic conversion of methane into benzene over ceria–zirconia‐promoted molybdenum‐supported zeolite for methane dehydroaromatization

Mishra

Modak

Pant

et al. 2023

Applied Organom Chemis

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The promotional effect of mixed ceria–zirconia oxides (CZO) over the Mo/HZSM‐5 catalyst for methane dehydroaromatization (MDA) reaction was studied. The surface and structural properties of the synthesized catalyst were thoroughly exemplified using various microscopic and spectroscopic tools, and the correlation between catalytic properties and its performance for MDA reaction is discussed. The impregnation of CZO solid solution on Mo/HZSM‐5 was monitored to give an excellent catalytic performance and improved benzene production rate (4.5 μmol/gcat.s) related to the conventionally prepared Mo/HZSM‐5 (3.1 μmol/gcat.s) catalyst. In addition, a significant reduction in coke formation was examined in the CZO‐modified Mo/HZSM‐5 catalyst. The prevailing comprehension for higher catalytic activity could be because of the redox properties of CZO‐deposited Mo/HZSM‐5, which acts as a selective oxygen supplier and performs hydrogen combustion during the reaction, which is indirectly probed by residual gas analysis‐mass spectroscopy, oxygen‐temperature programmed desorption, and hydrogen‐temperature programmed reduction analysis. The selective hydrogen combustion prevents the over‐oxidation of aromatic species formed during the reaction, whereas the generated steam helps in reducing the coke content deposition in the MDA reaction. Thus, the advantage of CZO‐incorporated Mo/HZSM‐5 is manifested as it promotes the reaction equilibrium to shift towards the formation of benzene which is favourable for MDA reaction.

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Characterization of Re-Mo/ZSM-5 catalysts: How Re improves the performance of Mo in the methane dehydroaromatization reaction

Cited by 14 publications

References 26 publications

MoO3 Nanobelt-Modified HMCM-49 Zeolite with Enhanced Dispersion of Mo Species and Catalytic Performance for Methane Dehydro-Aromatization

MoO3 Nanobelt-Modified HMCM-49 Zeolite with Enhanced Dispersion of Mo Species and Catalytic Performance for Methane Dehydro-Aromatization

Catalytic Routes for Direct Methane Conversion to Hydrocarbons and Hydrogen: Current State and Opportunities

Catalytic conversion of methane into benzene over ceria–zirconia‐promoted molybdenum‐supported zeolite for methane dehydroaromatization

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