Single-crystal structure analysis and energy minimizations of a MFI-type zeolite at low <i>p</i>-dichlorobenzene sorbate loading

Koningsveld, H. van; Jansen, J.C.; Man, Angela

doi:10.1107/s0108768195008512

Cited by 47 publications

(48 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Many structures consisting of MFI-type zeolites loaded with aromatic compounds have been determined using single-crystal XRD. [19][20][21][22][23][24][25][26] However, there are no reports concerning the locations of non-aromatic hydrocarbons, despite the heightened interest in this subject. These structures have not yet been determined due to the twinning problem, which makes the crystallographic analysis highly challenging.…”

Section: Introductionmentioning

confidence: 99%

Adsorption structures of non-aromatic hydrocarbons on silicalite-1 using the single-crystal X-ray diffraction method

Fujiyama

Seino

Kamiya

et al. 2014

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

The actual adsorption structures of non-aromatic hydrocarbons on the MFI-type zeolites have not yet been determined. This is due to the presence of twinning, which makes crystallographic analysis difficult. We recently overcame this problem, and now report the various adsorption structures of n-butane, n-pentane, n-hexane, 1-butene, cis and trans-2-butene, 2-butyne and isopentane on silicalite-1 (MFI-type zeolite) as determined via single-crystal X-ray diffraction. The structures were elucidated for both low and high loadings of each guest molecule in order to clarify the adsorption process. The low-loaded structures provide valuable insight into guest-framework interactions and initial adsorption behavior. The n-alkanes are initially adsorbed in the sinusoidal channel, while 2-butyne is adsorbed in the straight channel. In the case of the normal hydrocarbons, the molecular configuration (bent or linear) of the compound determines which channel is the preferred adsorption site. Bent molecules prefer the sinusoidal channel and linear molecules prefer the straight channel. In contrast, isopentane is initially adsorbed at the intersection, since the channels are too narrow to maintain the preferred distance between the framework and the bulky isopentane molecule. In the high-loaded structures, the guest molecules occupy additional sites, such that the normal hydrocarbons are located in both channels and isopentane is found at the intersection and the sinusoidal channel.

show abstract

Section: Introductionmentioning

confidence: 99%

Adsorption structures of non-aromatic hydrocarbons on silicalite-1 using the single-crystal X-ray diffraction method

Fujiyama

Seino

Kamiya

et al. 2014

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…For example, it has been shown that aromatic molecules, such as p -xylene, p -dichlorobenzene, and trans -stilbene, preferentially adsorb at different locations of the framework depending not only on the adsorbate nature but also on the adsorbate loading. 14 − 19 Techniques such as single-crystal X-ray diffraction and high-resolution synchrotron X-ray powder diffraction showed that at low loadings, the adsorbate molecules are preferentially located inside in the straight pores of ZSM-5 crystals, 14 − 16 whereas at high loadings, they accumulate at pore intersections and in the sinusoidal pores. 18 , 19 In addition, Eckman et al used deuterium solid-state NMR to trace temperature-dependent changes in orientation of p -xylene molecules in H-ZSM-5 at low loadings.…”

mentioning

confidence: 99%

“…As mentioned earlier, it has been described in the literature that the pore preference of p -dichlorobenzene depends on the adsorbate loading. 14 , 18 On this basis, we speculated that it should be possible to affect the pore preference of the catalytic reaction and direct the reaction to predominantly happen in one of both pore types. Numerous microspectroscopic studies have been conducted in the past to investigate the factors affecting catalytic activity of H-ZSM-5, such as its relation with the subcrystalline intergrowth structure, 24 − 26 , 29 − 33 the effect of commonly applied steaming treatments, 34 , 35 the mechanisms of coke formation, 36 and the solvent effect.…”

mentioning

confidence: 99%

Solvent Polarity-Induced Pore Selectivity in H-ZSM-5 Catalysis

et al. 2017

View full text Add to dashboard Cite

Molecular-sized micropores of ZSM-5 zeolite catalysts provide spatial restrictions around catalytic sites that allow for shape-selective catalysis. However, the fact that ZSM-5 has two main pore systems with different geometries is relatively unexploited as a potential source of additional shape selectivity. Here, we use confocal laser-scanning microscopy to show that by changing the polarity of the solvent, the acid-catalyzed furfuryl alcohol oligomerization can be directed to selectively occur within either of two locations in the microporous network. This finding is confirmed for H-ZSM-5 particles with different Si/Al ratios and indicates a general trend for shape-selective catalytic reactions.

show abstract

“…Studies to clarify the structures of sorbates in the ZSM-5 framework have been widely reported; single crystal X-ray diffraction is the most suitable method for elucidating these structures. Investigations of the sorbate-ZSM-5 structure by X-ray diffraction have been reported for toluene [1], naphthalene [2], dichlorobenzene [3,4], pnitroaniline [5,6], and many others.…”

Section: Introductionmentioning

confidence: 98%

“…However, the quality of most synthesized crystals is too low for single crystal X-ray diffraction. Lermer's synthesis is the best method thus far reported for producing large high-quality crystals [12][13][14]; this method was utilized in most of the sorbate-ZSM-5 investigations mentioned above [1][2][3][4]6]. However, this method also produces large quantities of the by-product analcime (Na 8 Al 8 Si 16 O 48 Á 8 H 2 O) ( Fig.…”

Section: Introductionmentioning

confidence: 98%

Large-quantity single crystal synthesis of TPA-ZSM-5 using KOH as a mineralizer

Kamiya¹,

Torii²,

Sasaki³

et al. 2007

Zeitschrift Für Kristallographie

View full text Add to dashboard Cite

Single crystals of TPA-ZSM-5 were synthesized using KOH as a mineralizer instead of NaOH. The size of the TPA-ZSM-5 crystals after 120 h was approximately 100 mm. When KOH was used, the quantity of TPA-ZSM-5 crystals formed was increased, and Al distribution in the crystal was uniform. The form and quality of these crystals were suitable for single crystal X-ray diffraction. Nucleation of the analcime by-product, which is formed in the presence of NaOH, is inhibited when KOH is used, because the potassium ion does not act as a template for the analcime structure. Instead, zeolite W was observed as a by-product. However, compared to analcime, the amount of zeolite W was lower, and it was easier to separate from TPA-ZSM-5. Thus, potassium ions play an important role in the production of large quantities of high-quality ZSM-5 with a uniform Al distribution.

show abstract

Single-crystal structure analysis and energy minimizations of a MFI-type zeolite at low p-dichlorobenzene sorbate loading

Abstract: The crystal structure of a low-loaded adsorption complex of H-ZSM-5 with p-dichlorobenzene has been studied by single-crystal X-ray diffraction.

Cited by 47 publications

References 9 publications

Adsorption structures of non-aromatic hydrocarbons on silicalite-1 using the single-crystal X-ray diffraction method

Adsorption structures of non-aromatic hydrocarbons on silicalite-1 using the single-crystal X-ray diffraction method

Solvent Polarity-Induced Pore Selectivity in H-ZSM-5 Catalysis

Large-quantity single crystal synthesis of TPA-ZSM-5 using KOH as a mineralizer

Contact Info

Product

Resources

About