Effects of hierarchical zeolites on aromatization of acetylene

Lee, Won Suk; Lee, Taehee; Jang, Hoi Gu; Cho, Sung June; Choi, Jungkyu; Ha, Kyoung-Su

doi:10.1016/j.cattod.2017.09.014

Cited by 14 publications

(6 citation statements)

References 51 publications

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“…Surprisingly, even Mo/SiO 2 , which possesses no BAS was much more active than H‐ZSM‐5 for benzene formation with a C 2 H 4 /H 2 /N 2 feed. Generally, when feeding ethylene, the selectivity to toluene (about the same as to benzene) seems to be higher than for MDA, while the selectivity to toluene and benzene mimics those of MDA more closely for acetylene/H 2 mixtures . Acetylene is not observed as a product of the MDA reaction, likely due to its high reactivity.…”

Section: What Is the Most Likely Intermediate?mentioning

confidence: 91%

“…Because of its high reactivity, the gas phase aromatization of acetylene over heterogeneous catalysts is hard to control and fast coking occurs even below 400 °C ,. The most recent report on this reaction investigated the effect of hierarchical zeolites at 700 °C, a temperature typically also applied for MDA . A very diluted stream of acetylene was co‐fed together with hydrogen and a BTX selectivity of up to 80 % was reached with benzene being the main product, and resembling the product distribution for MDA.…”

Section: Acetylene Aromatizationmentioning

confidence: 99%

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Progress in Developing a Structure‐Activity Relationship for the Direct Aromatization of Methane

et al. 2018

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To secure future supply of aromatics, methane is a commercially interesting alternative feedstock. Direct conversion of methane into aromatics combines the challenge of activating one of the strongest C−H bonds in all hydrocarbons with the selective aromatization over zeolites. To address these challenges, smart catalyst and process design are a must. And for that, understanding the most important factors leading to successful methane C−H bond activation and selective aromatization is needed. In this review, we summarize mechanistic insight that has been gained so far not only for this reaction, but also for other similar processes involving aromatization reactions over zeolites. With that, we highlight what can be learnt from similar processes. In addition, we provide an overview of characterization tools and strategies, which are useful to gain structural information about this particular metal‐zeolite system at reaction conditions. Here we also aim to inspire future characterization work, by giving an outlook on characterization strategies that have not yet been applied for the methane dehydroaromatization catalyst, but are promising for this system.

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Section: What Is the Most Likely Intermediate?mentioning

confidence: 91%

Section: Acetylene Aromatizationmentioning

confidence: 99%

Progress in Developing a Structure‐Activity Relationship for the Direct Aromatization of Methane

et al. 2018

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“…MCM-22 zeolite, synthesized in the 1990s, by the Mobile researches [1], due to its unusual pore structure, combining large 12 MR (Membered Ring) cavities and medium (10 MR channels) pores, as well as specific 2D alignment of the zeolitic layers, is under a great scientist's interest for possible application in catalysis. The up-to-date papers reporting catalytic activity of MCM-22 have shown its high efficiency in various reactions, including alkylation [2][3][4][5], aromatization [6,7], methanol-to-olefin (MTO) or -hydrocarbon (MTH) conversions [8,9], glycerol conversion [10,11], cracking reactions [12,13], Fischer-Tropsch synthesis [14], Knoevenagel condensation [15], α-pinene isomerization [16,17], and in various environmental processes [18,19].…”

Section: Introductionmentioning

confidence: 99%

Modification of MCM-22 Zeolite and Its Derivatives with Iron for the Application in N2O Decomposition

et al. 2020

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Layered 2D zeolite MCM-22 and its delaminated derivative, ITQ-2, were modified with iron, by different methods (ion-exchange and direct synthesis), and with the use of different precursors (FeSO4∙7H2O, Fe(NO3)3∙9H2O, and [Fe3(OCOCH3)7∙OH∙2H2O]NO3 oligocations. The applied modifications were aimed at optimization of iron form in the samples (aggregation, amount, location, and reducibility), in order to achieve the highest catalytic activity in the N2O decomposition. The synthesis of the samples was verified with the use of XRD (X-Ray Diffraction), N2-sorption and ICP-OES (Inductively Coupled Plasma Optical Emission Spectroscopy) techniques, while the form of iron in the samples was investigated by UV–vis-DRS (UV–vis diffuse reflectance spectroscopy), H2-TPR (Hydrogen Temperature-Programmed Reduction) and HRTEM (High-Resolution Transmission Electron Microscopy). The highest activity in the N2O decomposition presented the sample Fe(O,IE)MCM-22, prepared by ion-exchange of MCM-22 with Fe3(III) oligocations. This activity was related to the oligomeric FexOy species (the main form of iron in the sample) and the higher loading of active species (in comparison to the modification with FeSO4∙7H2O).

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“…The quantities of L or B acid sites ( Q ) were calculated according to eq where IA (B or L active sites) (cm –1 ) indicates the integrated absorbance band for L or B acid sites, A wafer (cm 2 ) is the self-supporting wafer’s cross-sectional area, W wafer (g) is the wafer weight, and C (cm/μmol) means the extinction coefficient. The extinction coefficients corresponding to the wavenumbers of ∼1540 and ∼1450 cm –1 are 1.13 and 1.28 cm/μmol, respectively. , …”

Section: Methodsmentioning

confidence: 93%

“…The quantities of L or B acid sites (Q) were calculated according to eq 1 corresponding to the wavenumbers of ∼1540 and ∼1450 cm −1 are 1.13 and 1.28 cm/μmol, respectively. 44,45 Adsorption Studies. The standard solutions were prepared by dissolving 50 mg of Nap in 50 mL of methanol, and the concentrations of the stock standard solutions were 1000 mg/L.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Tailored Design of Differently Modified Mesoporous Materials To Deeply Understand the Adsorption Mechanism for Polycyclic Aromatic Hydrocarbons

Yuan

Wang

et al. 2018

Langmuir

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A series of SBA-15 with different modifications have been successfully prepared and applied as adsorbents to remove polycyclic aromatic hydrocarbons (PAHs) from aqueous solutions. The morphology and structural properties of the chemically modified materials are all similar to those of pure SBA-15, and thus the difference of PAHs adsorption capacity can be directly attributed to the different functional groups, which is favorable to deeply explore the adsorption mechanism. Adsorption kinetics and isotherm experiments for naphthalene (Nap), anthracene (Ant), and pyrene (Pyr) were carried out, and the results reveal that the adsorption processes follow a pseudo-second-order rate equation and the equilibrium can be achieved within 120 min for Nap and Ant, whereas only 90 min for Pyr, indicating that the more hydrophobic molecules, the easier and faster adsorption can be obtained. All of the adsorption isotherms fit well with the Freundlich model, suggesting the unevenly distributed active sites on adsorbents. The phenyl-functionalized materials possess the highest adsorption capacity, implying that the π–π interaction is the most primary interaction and plays the predominant role in the studied PAHs adsorption, superior to the acidic and hydrophobic interaction. Our research sheds light on the design and synthesis of advanced and highly efficient adsorbents to remove PAHs from aqueous solutions.

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Effects of hierarchical zeolites on aromatization of acetylene

Cited by 14 publications

References 51 publications

Progress in Developing a Structure‐Activity Relationship for the Direct Aromatization of Methane

Progress in Developing a Structure‐Activity Relationship for the Direct Aromatization of Methane

Modification of MCM-22 Zeolite and Its Derivatives with Iron for the Application in N2O Decomposition

Tailored Design of Differently Modified Mesoporous Materials To Deeply Understand the Adsorption Mechanism for Polycyclic Aromatic Hydrocarbons

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