Post-transformation of MWW-type lamellar precursors into MCM-56 analogues

Wang, Lingling; Wang, Yong; Liu, Yueming; Chen, Li; Cheng, Shifu; Gao, Guohua; He, Min; Wu, Peng

doi:10.1016/j.micromeso.2007.11.044

Cited by 64 publications

(52 citation statements)

References 28 publications

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“…Following our previous procedures for post-synthesizing MCM-56 analogues of titanosilicate and aluminosilicate [23,24], the structural transformation to Sn-MCM-56 was attempted by carrying out acid treatment on as-synthesized Sn-MCM-22(P) precursor in 2 M HNO 3 solution (solid-to-liquid ratio of 1:50) at room temperature for 6 h. The acid-treated sample was subsequently calcined in air at 823 K for 10 h to remove residuary organic species of SDA. For control experiment, the MWW precursor was refluxed in HNO 3 solution to obtain Sn-MCM-22(A) with a conventional 3D MWW structure.…”

Section: Synthesis Of Materialsmentioning

confidence: 99%

“…This kind of unique structure might facilitate the reactant molecules to reach the active centers and therefore improve catalytic activity. We once showed that it is possible to post-synthesize the titanosilicate and aluminosilicate with a structure analogous to MCM-56 from corresponding MWW lamellar precursors that are fully crystallized by hydrothermal synthesis [23,24].…”

Section: Postsynthesis Of Sn-mcm-56 Analoguesmentioning

confidence: 99%

“…The aforementioned post-modification techniques have increased research interests in preparing the MWW structure-related metallosilicates. The effectiveness of this post-synthesis has been demonstrated in the structural changes of both titanosilicate (Ti-MWW) [23] and aluminosilicate (MCM-22) [24]. Accordingly, it is of potential significance to introduce tin ions into the framework of MWW zeolite and then to convert the tin-containing precursor into more efficient catalysts.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Hydrothermal synthesis of MWW-type stannosilicate and its post-structural transformation to MCM-56 analogue

Liu

Jiang

Yang

et al. 2013

Microporous and Mesoporous Materials

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Section: Synthesis Of Materialsmentioning

confidence: 99%

Section: Postsynthesis Of Sn-mcm-56 Analoguesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Hydrothermal synthesis of MWW-type stannosilicate and its post-structural transformation to MCM-56 analogue

Liu

Jiang

Yang

et al. 2013

Microporous and Mesoporous Materials

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“…We believe that the permanence of our delamination approach is facilitated by lattice distortions along both the c-axis and the a-b plane, which are induced by substitution of Al for B. Other examples of surfactant-free synthesis of more accessible zeolites include synthesis of MCM-56 analogues, [14][15][16] IPC-1P, 17 IPC-1PI, 18 IPC-2 and IPC-4. 19 Synthesis of heteroatom-substituted zeolites where heteroatoms are located in framework T-positions of all-silica analog zeolites is invaluable for zeolite catalysis.…”

Section: Introductionmentioning

confidence: 99%

Novel surfactant-free route to delaminated all-silica and titanosilicate zeolites derived from a layered borosilicate MWW precursor

et al. 2014

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a Layered borosilicate zeolite precursor ERB-1P (Si/B = 11) is delaminated via simultaneous deboronation and SDA removal, to yield material DZ-1 consisting of silanol nests, using a simple aqueous Zn(NO 3 ) 2 treatment. Characterization of this synthesis process by PXRD shows loss of long-range order, and transmission electron microscopy (TEM) demonstrates transformation of rectilinear layers in the layered zeolite precursor to single and curved layers in the delaminated material. N 2 physisorption confirms the expected decrease of micropore volume and increase in external surface area for delaminated materials relative to their calcined 3D zeolite counterpart. Elemental analysis shows loss of B and absence of Zn in the delaminated material. Resonances corresponding to silanol nests are evident via 29Si solid-state NMR spectroscopy in DZ-1, which should be located within 12-MR pockets near the external surface. We have successfully utilized these nests as tetrahedral recognition sites for incorporation of Ti within an isolated framework coordination environment in material Ti-DZ-1. Diffuse-reflectance ultraviolet (DR-UV) spectroscopy of Ti-DZ-1 confirms isolated framework Ti sites, which are assigned to bands in the range of 210 nm-230 nm. Infrared spectra of Ti-DZ-1 consist of a distinct absorption band at 960 cm, which is absent in DZ-1 prior to Ti incorporation and has been previously correlated with the presence of framework Ti species. Infrared spectra after pyridine adsorption demonstrate bands consistent with Lewis-acid sites in the resulting Ti-substituted delaminated zeolite. The accessibility of these Lewis-acid sites is confirmed when using Ti-DZ-1 as a catalyst for cyclohexene epoxidation using tert-butyl hydroperoxide as the organic oxidant -a reaction for which both DZ-1 and TS-1 are inactive.

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“…Therefore, developing alternative titanosilicates with large external surface and rich exposed Ti sites to dibenzothiophene molecules still has a challenge. Wang et al [ 100 ] developed a post-synthesis methodology to prepare a titanosilicate catalyst from acid-treating the 3D Ti-MWW precursors at low temperatures, leading to high crystalline Ti-MCM-56 analogues after calcination. Compared with 3D Ti-MWW, the Ti-MCM-56 analogues has a much larger external surface, which mitigated effectively the steric restrictions to bulky molecules.…”

Section: Oxidative Desulfurization Over Ti-mcm-56mentioning

confidence: 99%

Catalytic Oxidations Over Titanosilicate Zeolites

Wang

Xiao

2016

Green Chemistry and Sustainable Technology

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An important topic in the fi eld of zeolite is the titanosilicate with tetrahedral Ti sites, which have already been regarded as effi cient catalyst for the oxidation of various organic substrates by hydrogen peroxide. Since the fi rst report of TS-1 zeolite in 1983, a variety of titanosilicates with various morphologies have been synthesized and applied in the oxidation reactions. The physical parameters of structures, porosities, Ti loadings, and wettabilities strongly determine the catalytic properties of the titanosilicate catalysts. The TS-1 zeolite is effi cient for the hydroxylation of benzene and phenol, as well as the epoxidation and ammoxidation of olefi ns and ketons with small molecule size. Ti-Beta with larger micropores than TS-1 exhibits excellent catalytic performances in the oxidation of bulky molecules. Ti-MWW zeolites with a unique two-dimensional structure are also used in the oxidation of olefi ns, ammoxidation of ketons, and oxidative desulfurization.

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Post-transformation of MWW-type lamellar precursors into MCM-56 analogues

Cited by 64 publications

References 28 publications

Hydrothermal synthesis of MWW-type stannosilicate and its post-structural transformation to MCM-56 analogue

Hydrothermal synthesis of MWW-type stannosilicate and its post-structural transformation to MCM-56 analogue

Novel surfactant-free route to delaminated all-silica and titanosilicate zeolites derived from a layered borosilicate MWW precursor

Catalytic Oxidations Over Titanosilicate Zeolites

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