On methanol to hydrocarbons reactions in a hierarchically structured ZSM-5 zeolite catalyst

Kim, Hee-Joong; Jang, Hoi Gu; Jang, Eun-Hee; Park, Sung Jun; Lee, Taehee; Jeong, Yanghwan; Baik, Hionsuck; Cho, Sung June; Choi, Jungkyu

doi:10.1016/j.cattod.2017.09.032

Cited by 23 publications

(9 citation statements)

References 48 publications

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“…HZSM-5 is the general component of catalysts for olefin synthesis from oxygenates (dimethyl ether or methanol) [1]. Investigations of MTH (methanol-to-hydrocarbons) catalysts are focused on studying the effect of crystal size, the module of the HZSM-5 zeolite, binder type, dealumination degree, the presence of mesopores, and the physical chemical properties of catalyst, such as crystallinity, acidity, specific surface area, and the volume of micro-and mesopores [2][3][4][5][6][7][8]. The total number of works in the field of catalysts for propylene synthesis from methanol in the last 5 years has more than 200.…”

Section: Introductionmentioning

confidence: 99%

Dimethyl Ether to Olefins over Modified ZSM-5 Based Catalysts Stabilized by Hydrothermal Treatment

et al. 2019

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The reaction of dimethyl ether to olefin over HZSM-5/Al2O3 catalysts modified by Zr and Mg and stabilized by hydrothermal treatment has been studied. Regardless of the introduction method and the nature of the metal, the dependence of the key products selectivity on X(DME) over hydrothermally treated steady-state catalysts does not change, and the experimental points are described by the same curves. Metal introduction and the corresponding changes in the acid sites distribution do not change the ratio of main reaction rates, only the absolute values of the formation rate of the products are changed. Zr doping leads to the greatest activity in the DME conversion due to an equable decrease in the total acidity of the sample. On the other hand, the Mg-modified sample has a higher amount of weak acid sites, which reduces activity. At low DME conversion, methanol is one of the primary reaction products which formed from DME simultaneously with propylene in alkene cycle. At high DME conversion, the methanol acts as a main reagent which leads to ethylene formation in the arene cycle. Based on the results, the role of the metal in the reaction chemistry is considered and the mechanism of product formation from DME over steady-state catalyst is proposed, which describes both the participation of DME and the methanol produced.

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Section: Introductionmentioning

confidence: 99%

Dimethyl Ether to Olefins over Modified ZSM-5 Based Catalysts Stabilized by Hydrothermal Treatment

et al. 2019

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“…The nanosheet-assembled ZSM-5 was synthesized following the literature, but the ethanol derived from the hydrolysis of tetraethyl orthosilicate was removed to increase mesoporosity. , In a typical experiment, 10.366 g of tetrabutylphosphonium hydroxide (TBPOH, 40% in water; J&K) was dropwise added into 10.629 g of tetraethyl orthosilicate (TEOS, 98%; J&K) under stirring conditions. Subsequently, a sodium hydroxide solution (prepared with 4.58 g of H 2 O and 0.03 g of NaOH) was added to the above mixture.…”

Section: Experimental Sectionmentioning

confidence: 99%

“…Figure 1 presents the X-ray diffraction (XRD) patterns of the obtained samples. All zeolite samples exhibited the characteristic diffraction peaks of the ZSM-5 structure, 34,35 suggesting that the incorporation of Fe species into the zeolite matrix did not affect the topological structure of zeolites. In addition, no identified diffraction peaks belonging to large iron oxide particles were detected for all Fe@ZSM-5, suggesting that the Fe species were predominantly incorporated as isolated irons or highly dispersed into the ZSM-5 zeolite framework mainly as small crystalline iron oxide particles.…”

Section: Introductionmentioning

confidence: 99%

Fe-Encapsulated ZSM-5 Zeolite with Nanosheet-Assembled Structure for the Selective Catalytic Reduction of NO_x with NH₃

Liu

Zheng

Liao

et al. 2020

Ind. Eng. Chem. Res.

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A series of iron-encapsulated hierarchical ZSM-5 zeolites with nanosheet-assembled structure were designed and successfully fabricated, and their catalytic performance was investigated for the selective catalytic reduction of NO x with NH 3 (NH 3 -SCR). Because of the synergy between the welldispersed Fe active species and the Brønsted acidic framework of zeolites, the Fe-containing ZSM-5 catalyst displayed excellent catalytic performance, and density functional theory (DFT) calculation data indicated that capturing NH 3 was the main factor that mediates the NH 3 -SCR process. In addition, the resultant zeolite catalysts exhibited a good resistance to SO 2 and H 2 O, which was very competitive for practical application to reduce NO x emissions. Furthermore, in situ DRIFT measurements revealed that the generation of inactive nitrate species led to the decrease of zeolite activity in a high-temperature region.

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“…Moreover, the acidity of ZSM-5 has been shown to be a key factor influencing the nature of the products, commonly adjusted by zeolite modification by changing the Si/Al ratio . As an example, several scientists described the remarkable presence of olefins on ZSM-5 catalysts with a high Si/Al ratio, which resulted in boosted selectivity via hydrogen transfer in the methanol to olefins (MTO) process; however, the catalysts with low-Si/Al-ratio ZSM-5 were found to be adequate candidates for aromatics production in the methanol to hydrocarbons (MTH) reaction. − …”

Section: Introductionmentioning

confidence: 99%

High-Impact Promotional Effect of Mo Impregnation on Aluminum-Rich and Alkali-Treated Hierarchical Zeolite Catalysts on Methanol Aromatization

Ghanbari

Zangeneh

Rizi³

et al. 2020

ACS Omega

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A systematic change of HZSM-5 (HZ5) as a catalyst of the methanol to aromatics (MTA) reaction was undertaken by employing a fixed-bed tubular-type reactor under ambient pressure, applying a weight hourly space velocity (WHSV) of 2 h–1 at 375 °C, as the first report on the application of low-Si/Al-ratio alkaline-[Mo,Na]-HZSM-5 in the MTA process. To characterize the surface and textural properties of the catalysts, powder X-ray diffraction (PXRD), nitrogen adsorption/desorption, temperature-programmed desorption of ammonia (NH3-TPD), pyridine-infrared spectroscopy (Py-IR), thermogravimetric analysis (TGA), and energy-dispersive X-ray (EDX) methods were employed. Gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) measurements demonstrated a selectivity of up to 86 wt % (65.7 wt % for benzene, toluene, and xylene (BTX)) over 2[Mo]HZ5. NH3-TPD and Py-IR results indicated a sensible decrease of strong acid sites on the impregnated samples, while the surface analyses revealed the highest Lewis acid sites (LAS) together with the largest mesopore surface area for 2[Mo]alk-HZ5, supporting the migration of Mo species to the bulk of the catalysts. Mo impregnation had a minor effect on the observed coke formation in the promoted catalyst.

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On methanol to hydrocarbons reactions in a hierarchically structured ZSM-5 zeolite catalyst

Cited by 23 publications

References 48 publications

Dimethyl Ether to Olefins over Modified ZSM-5 Based Catalysts Stabilized by Hydrothermal Treatment

Dimethyl Ether to Olefins over Modified ZSM-5 Based Catalysts Stabilized by Hydrothermal Treatment

Fe-Encapsulated ZSM-5 Zeolite with Nanosheet-Assembled Structure for the Selective Catalytic Reduction of NO_x with NH₃

High-Impact Promotional Effect of Mo Impregnation on Aluminum-Rich and Alkali-Treated Hierarchical Zeolite Catalysts on Methanol Aromatization

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On methanol to hydrocarbons reactions in a hierarchically structured ZSM-5 zeolite catalyst

Cited by 23 publications

References 48 publications

Dimethyl Ether to Olefins over Modified ZSM-5 Based Catalysts Stabilized by Hydrothermal Treatment

Dimethyl Ether to Olefins over Modified ZSM-5 Based Catalysts Stabilized by Hydrothermal Treatment

Fe-Encapsulated ZSM-5 Zeolite with Nanosheet-Assembled Structure for the Selective Catalytic Reduction of NOx with NH3

High-Impact Promotional Effect of Mo Impregnation on Aluminum-Rich and Alkali-Treated Hierarchical Zeolite Catalysts on Methanol Aromatization

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Fe-Encapsulated ZSM-5 Zeolite with Nanosheet-Assembled Structure for the Selective Catalytic Reduction of NO_x with NH₃