Properties of layered [Al]- and [V,Al]-magadiite catalysts as revealed by ethanol dehydration

Almeida, Ramon K.S.; Paz, Gizeuda L.; Báfero, Gabriel B.; Pastore, Heloise O.

doi:10.1016/j.micromeso.2019.04.002

Cited by 12 publications

(20 citation statements)

References 37 publications

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“…This explains the proximity of values for chemical shifts and quadrupole constants for both cations. The convolution of both signals formed a 23 Na NMR spectrum in a good agreement with the experimental spectra , (SI Figure 12a).…”

Section: Resultssupporting

confidence: 77%

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The Elusive Structure of Magadiite, Solved by 3D Electron Diffraction and Model Building

et al. 2021

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In addition to a great swelling ability, layered silicates also allow the functionalization of their interlayer region to form various robust green materials that are used as CO 2 adsorbents, drug carriers, or catalysts. Here, the unique magadiite structure, which has resisted elucidation despite many attempts and applications the material offers, is finally described. A materialspecific strategy allowed the use of 3D electron diffraction which led to the success of deciphering the atomic structure. In order to enable an ab initio structure solution of the electron beam sensitive material, a sodium-free dehydrated form of magadiite was synthetically isolated, and, from that, it was subsequently possible to derive a structure model for the sodium form of magadiite, later successfully refined against powder X-ray diffraction data. Furthermore, a geometry optimization and simulations of spectroscopic data with DFT methods confirm the obtained crystal structure of sodium magadiite. These results finally prompted a detailed description of the layers and of the chemically active interlayer region and provide a huge impact toward the design of new and more efficient materials based on functionalized magadiite and related structures.

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Section: Resultssupporting

confidence: 77%

“…In the case of the Si nuclei (SI Figure 12b), three distinguishable sets of Si-Q 4 and Si-Q 3 types were identified based on the agreement between experimental , and simulated NMR spectra. The calculated 1 H NMR spectrum (SI Figure 12c) contains two peaks.…”

Section: Resultsmentioning

confidence: 99%

The Elusive Structure of Magadiite, Solved by 3D Electron Diffraction and Model Building

et al. 2021

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“…only been investigated as a catalyst in liquid-phase reactions performed in organic solvent 81,82 or in the gas phase. 48,49 To assess any modification in the catalysts upon reaction, the catalysts were collected right after 7 h time on stream and analyzed as concerning their structure and Al chemical environment as assessed by XRD and solid-state 27 Al NMR, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…As far as we could track, this is the first time that the [Al]-magadiite water-tolerant acidity is reported in the literature. Indeed, so far, [Al]-magadiite has only been investigated as a catalyst in liquid-phase reactions performed in organic solvent , or in the gas phase. , …”

Section: Results and Discussionmentioning

confidence: 99%

“…Superti and co-workers and Moura and co-workers demonstrated the presence of tetrahedral and octahedral aluminum sites in [Al]-magadiite without modifications in its stability and structure. Paz et al reported that this aluminosilicate presents weak to moderate acidity depending on the Si/Al molar ratio and that it is active in ethanol dehydration reaction. , There is no information, however, on its performance in liquid water reactions whether or not related to biomass conversion. Therefore, it holds back the exploitation of magadiite on aqueous-phase processing (APP) in general, but it is a particular loss for biomass-derived compounds, which are abundant low-vapor-pressure molecules widely soluble in water.…”

Section: Introductionmentioning

confidence: 99%

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Continuous Cellobiose Hydrolysis over Lamellar Aluminosilicates—Unveiling [Al]-magadiite Water-Tolerant Acid Sites

Campos

Albuquerque

Fraga

et al. 2021

Ind. Eng. Chem. Res.

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Cellobiose hydrolysis was investigated over acid-layered solids H-[Al]-magadiite in a continuously operated fixed bed flow reactor. Catalysts containing different Si/Al molar ratios were synthesized to tune distinct acidity. The incorporation of Al into the silicate framework created indeed active acid sites for cellobiose hydrolysis reaction. The catalyst with the highest Al content (Si/Al = 17) was the most active, displaying a constant cellobiose conversion of ∼80%. Glucose was the main product observed; however, fructose and 5-hydroxymethylfurfural (HMF) were also detected. The results indicated that H-[Al]-magadiite catalysts have Lewis acid sites that are active even in the presence of water. Characterization analysis performed on catalysts after the reaction showed that the [Al]-magadiite structure was maintained and no Al leaching was observed.

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Comparison of the hydrothermal syntheses of Sn-magadiite using Na2SnO3 and SnCl4·5H2O as the precursors

Santos

Silva

Meneghetti

2019

Applied Clay Science

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Properties of layered [Al]- and [V,Al]-magadiite catalysts as revealed by ethanol dehydration

Cited by 12 publications

References 37 publications

The Elusive Structure of Magadiite, Solved by 3D Electron Diffraction and Model Building

The Elusive Structure of Magadiite, Solved by 3D Electron Diffraction and Model Building

Continuous Cellobiose Hydrolysis over Lamellar Aluminosilicates—Unveiling [Al]-magadiite Water-Tolerant Acid Sites

Comparison of the hydrothermal syntheses of Sn-magadiite using Na2SnO3 and SnCl4·5H2O as the precursors

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