Improving the Hydrothermal Stability of Mesoporous Silica SBA-15 by Pre-treatment with (NH4)2SiF6

Song, Mingjuan; Zou, Chenglong; Niu, Guoxing; Zhao, Dongyuan

doi:10.1016/s1872-2067(10)60283-5

Cited by 17 publications

(3 citation statements)

References 30 publications

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“…It is worth noting that the micropore size of modified ZSM‐5 was neither significantly reduced nor increased after the further introduction of K + , and this is probably because of an offsetting effect between re‐created pores and blocked pores. Except for K−Si(0.1 M)‐ZSM‐5, an increase in AHFS concentration followed by the introduction of K + resulted in a slight increase in the micropore and mesopore size of HZSM‐5, and this is probably because some SiO 2 is deposited on the wall and because the introduced K + blocks some channels of HZSM‐5 when the concentration of AHFS is low (0.1 M) …”

Section: Resultsmentioning

confidence: 99%

Selective Adsorption of p‐Cresol from a Mixture of m‐Cresol and p‐Cresol over ZSM‐5 with Controlled Micro‐ and Mesoporosity

Guo

et al. 2019

ChemistrySelect

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Ammonium hexafluorosilicate (AHFS) 1 at different concentrations was utilized as a mesopore‐generating agent to synthesize hierarchical ZSM‐5 (Si‐ZSM‐5) adsorbents; K+‐exchanged hierarchical ZSM‐5 (K−Si‐ZSM‐5) was successfully prepared by an impregnation method. The properties of adsorbents were characterized using XRD, XRF, N2 adsorption‐desorption and NH3‐TPD. The selectivity separation of p‐cresol 2 and m‐cresol 3 on adsorbents were experimentally investigated using a liquid breakthrough method. The enhanced adsorption capacity of Si‐ZSM‐5 is attributed to the creation of mesopores, which probably led to higher adsorption diffusion. The introduction of K+ into hierarchical ZSM‐5 diminishes the acid sites, strengthens adsorption sites, and reduces the mesopore diameter. Thus, K−Si‐ZSM‐5 possessed higher separation efficiency compared with the parent HZSM‐5. The concentration of AHFS had significant impact on adsorption capacity and the separation efficiency of adsorbents, and AHFS at a concentration of 0.5 M exhibited the optimal adsorption performance. Furthermore, the adsorbent is easy to prepare under laboratory conditions, and through a large scaled‐up breakthrough experiment, it is suitable for practical industrial applications. Also, we propose separation mechanisms of m‐cresol 3 and p‐cresol 2, and these are mainly controlled by shape selection and adsorbent‐adsorbent interactions.

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Section: Resultsmentioning

confidence: 99%

Selective Adsorption of p‐Cresol from a Mixture of m‐Cresol and p‐Cresol over ZSM‐5 with Controlled Micro‐ and Mesoporosity

Guo

et al. 2019

ChemistrySelect

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“…Figure 5 shows the Py-IR spectra of HZSM-5, Zn/HZSM-5, and Zn-2P/HZSM-5 catalysts evacuated at Meanwhile, new L acid sites (L 1615 ), as confirmed by the Py-IR adsorption peak around 1615 cm −1 , [43,50] are produced. The redistribution of B and L acid sites could be ascribed to the strong interaction between the intrinsic acid sites and the zinc species, and thus partial B acid sites on the HZSM-5 catalyst are converted into Zn-L acid sites.…”

Section: Catalyst Characterizationmentioning

confidence: 92%

“…The increase in crystallinity could be ascribed to the silicon species produced by the hydrolysis of SiF 6 2− , which interacts with the framework of zeolite and repairs partial lattice defects. [42,43] The NH 3 -temperature-programmed desorption profiles of HZSM-5, 0.5P/HZSM-5, 2P/HZSM-5, and Zn-2P/HZSM-5 catalysts are shown in Figure 3. Two typical desorption peaks of the HZSM-5 zeolite, centered at about 270 C (low-temperature peak) and 480 C (hightemperature peak), were observed with all investigated ZSM-5 samples.…”

Section: Catalyst Characterizationmentioning

confidence: 99%

Highly shape‐selective Zn‐P/HZSM‐5 zeolite catalyst for methanol conversion to light aromatics

Jia

Wang

Zhang

et al. 2020

Applied Organom Chemis

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A highly shape-selective and relatively long-lifetime HZSM-5-based catalyst (Zn-2P/HZSM-5) was prepared by chemical modification with both ZnSiF 6 Á6H 2 O and H 3 PO 4 solution. The phosphoric acid modification could effectively modulate the Brønsted acid strength of the HZSM-5 catalyst, which promotes the oligomerization, alkylation, cyclization, and hydrogen transfer reactions. The introduction of Zn-Lewis acid sites significantly improved the dehydroaromatization of higher olefins. All of these were very beneficial for the generation of BTX (i.e. benzene, toluene, and xylene) hydrocarbons in aromatization of methanol. The coke amount and the average rate of coke formation decreased over the Zn-2P/HZSM-5 catalysts, which may largely be ascribed to its lower strong acid sites and lower outer surface acidity. The catalytic performance of methanol aromatization showed that the Zn-2P/HZSM-5 catalyst exhibited the highest BTX selectivity of about 46.76% and the longest catalytic lifetime of about 498 h at T = 400 C, P = 0.1 MPa, and weight hourly space velocity = 0.7 h −1 .

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Hydroprocessing of Phenanthrene Over Sulfided Fe–W Supported on Modified SBA-15

2017

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Improving the Hydrothermal Stability of Mesoporous Silica SBA-15 by Pre-treatment with (NH4)2SiF6

Cited by 17 publications

References 30 publications

Selective Adsorption of p‐Cresol from a Mixture of m‐Cresol and p‐Cresol over ZSM‐5 with Controlled Micro‐ and Mesoporosity

Selective Adsorption of p‐Cresol from a Mixture of m‐Cresol and p‐Cresol over ZSM‐5 with Controlled Micro‐ and Mesoporosity

Highly shape‐selective Zn‐P/HZSM‐5 zeolite catalyst for methanol conversion to light aromatics

Hydroprocessing of Phenanthrene Over Sulfided Fe–W Supported on Modified SBA-15

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