Catalytic Performance of Al-MCM-41 Catalyst for the Allylation of Aromatic Aldehydes with Allyltrimethylsilane: Comparison with TiCl4 as Lewis acid

Brahmi, Lamia; Ali-Dahmane, Tewfik; Hamacha, Rachida; Hacini, Salih

doi:10.1016/j.molcata.2016.06.004

Cited by 33 publications

(18 citation statements)

References 44 publications

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“…Notwithstanding, all solids maintained a uniform and unimodal pore size distribution as shown in Figure 2. The total pore volume (0.68 -1.06 cm 3 g -1 ) and the average pore diameter (2.56 -2.65 nm) are consistent with the physical nature of the MCM-41 and Al-MCM-41 mesoporous molecular sieves 11,13 . In addition, the pore wall-thickness (W t ) increased from 1.37 to 1.63 nm with the increase of Al content.…”

Section: Resultssupporting

confidence: 69%

“…The XRD patterns of all samples exhibit a very strong and well-resolved peak at 2Ө = 2.5° assigned to the reflection line (100), and very weak and broad two peaks at 2Ө = 4.3° and 4.9°, corresponding to the reflections lines (110) and (200), respectively. The intense reflection line (100) is characteristic of the hexagonal structure (space group p6mm) of the purely siliceous MCM-41 (ICDD#49-1712) and the presence of the reflection lines (110) and (200) confirm the highly crystallinity and the well-defined hexagonally ordered pore geometry of the mesoporous materials [1][2][3]13 . However, when Al was incorporated in the purely siliceous MCM-41 the main reflection line (100) became broader and less intense, even at very low levels of aluminum content, and the reflection lines (110) and (200) are hardly observed.…”

Section: Resultsmentioning

confidence: 89%

“…Furthermore, with the rise of aluminum content or decrease of the Si/Al ratio, the d-spacing values (d 100 ) increased and, consequently, the unit cell parameters (a 0 ) expanded ( Table 2). The increase of the interplanar spacing suggests that aluminum was incorporated into the structure of MCM-41 and this could be due to the difference in size between aluminum ions, Al +3 (radius = 53 pm) and silicon ions, Si +4 (radius = 40 pm) 13,18,21 . The latter are in agreement with the literature, and independent of the synthesis method, it is commonly accepted that the incorporation of Al +3 ions in the MCM-41 structure produce an expansion on its crystalline reticulum causing a narrowing of the pore size and a decrease in the crystallinity degree of the mesoporous materials 13,18,19,21,22 .…”

Section: Resultsmentioning

confidence: 99%

“…The increase of the interplanar spacing suggests that aluminum was incorporated into the structure of MCM-41 and this could be due to the difference in size between aluminum ions, Al +3 (radius = 53 pm) and silicon ions, Si +4 (radius = 40 pm) 13,18,21 . The latter are in agreement with the literature, and independent of the synthesis method, it is commonly accepted that the incorporation of Al +3 ions in the MCM-41 structure produce an expansion on its crystalline reticulum causing a narrowing of the pore size and a decrease in the crystallinity degree of the mesoporous materials 13,18,19,21,22 . In respect to the N 2 adsorption-desorption isotherms obtained at 77 K, the profiles for purely siliceous and Alcontaining samples corresponded to type IV (in the IUPAC classification), which is typical of the MCM-41 mesoporous molecular sieves with well-defined and ordered cylindrical mesopores [1][2][3] .…”

Section: Resultsmentioning

confidence: 99%

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Influence of Aluminum Addition in the Framework of MCM-41 Mesoporous Molecular Sieve Synthesized by Non-Hydrothermal Method in an Alkali-Free System

et al. 2017

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Purely siliceous MCM-41 and Al-containing MCM-41 (Al-MCM-41) mesoporous materials were synthesized by non-hydrothermal method in alkali-free ions medium at room temperature and short reaction times. Under these synthesis conditions, it was also investigated the influence of Al incorporation in the crystal structure of MCM-41. The solids were characterized by ICP-OES, AAS, N 2 adsorption at 77 K, XRD, TEM, NH 3 -TPD, 27 Al and 29 Si-MAS-NMR, FT-IR and TGA. The resulting mesoporous materials showed a well-defined hexagonally ordered pore geometry maintaining a uniform and unimodal pore size distribution with high specific surface areas (1000-1400 m 2 g -1 ). The Al +3 ions were introduced successfully in the structure of the purely siliceous MCM-41 expanding the unit cell parameter and forming four-coordinated Al species, and in a less extent, forming six-coordinated Al species. In addition, the surface acidity of the MCM-41 increased with Al loading. Contrary, the presence of Al in the MCM-41 mesoporous structure resulted in a decrease of the crystallinity and specific surface area possibly due to the presence of Al species in highly distorted tetrahedral structures and Al extra-framework or amorphous alumina occluded in the pores. The MCM-41 type mesoporous materials obtained in this work show similar characteristics of those synthesized by conventional hydrothermal methods.

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Section: Resultssupporting

confidence: 69%

Section: Resultsmentioning

confidence: 89%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Influence of Aluminum Addition in the Framework of MCM-41 Mesoporous Molecular Sieve Synthesized by Non-Hydrothermal Method in an Alkali-Free System

et al. 2017

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“…The synthesis and characterization the Sior Al-MCM-standard, were given elsewhere [7,33]. The molar chemical composition used was: SiO2 : 0.25 CTAB : 0.2 TMAOH : 0.04 Al2O3 : 40 H2O.…”

Section: Synthesis Of Mcm-standardmentioning

confidence: 99%

Comparison of Lewis Acidity between Al-MCM-41 Pure Chemicals and Al-MCM-41 Synthesized from Bentonite

Ali-Dahmane

Brahmi

Hamacha

et al. 2019

Bull. Chem. React. Eng. Catal.

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This study focused on the Lewis acidity of Al-MCM-41 prepared from bentonite (Al-MCM-bentonite) as silica and aluminum source simultaneously. This acidity was compared with Al-MCM-41 synthesized from pure chemicals reagents (Al-MCM-standard). Structural analysis showed that the substitution of the silicon atom by the aluminum atom decreases the structural order of Al-MCM-standard, whereas Al-MCM-bentonite has a better structural organization. The Lewis acidity of the Al-MCM-bentonite was evaluated in allylation reaction of benzaldehyde with allyltrimethylsilane and pyridine adsorption experiments. The results showed that the difference in acidity between Al-MCM-standard and Al-MCM-bentonite is due to the amount of aluminum incorporated into the framework of our mesoporous materials. According to the EDX analysis, the incorporation of aluminum in Al-MCM-standard (Si/Al = 13.47) is more important than in Al-MCM-bentonite (Si/Al = 43.64). This explains the low acidity of Al-MCM-bentonite, and the moderate yields in the allylation reactions of benzaldehyde with allyltrimethylsilane.

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Heterogeneous catalyzed isomerization of turpentine oil by ordered mesoporous materials like M41S structures

et al. 2022

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Herein, the synthesis of a structure with a porous system similar to that of molecular sieves, MCM‐41 and 48 types, with the incorporation of heteroatoms in their synthesis, is reported. The catalytic activity of these materials was tested in the isomerization reaction of turpentine oil to obtain camphene. The best results were obtained with Zn‐Al‐Si‐MCM, a mesoporous material, with a conversion of up to 96% and selectivities of 31% and 22% to camphene and 4‐carene, respectively, both of which are bicyclic products. The recycling of the catalyst was also tested, and after three cycles, no significant loss of activity was observed.

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Catalytic Performance of Al-MCM-41 Catalyst for the Allylation of Aromatic Aldehydes with Allyltrimethylsilane: Comparison with TiCl4 as Lewis acid

Cited by 33 publications

References 44 publications

Influence of Aluminum Addition in the Framework of MCM-41 Mesoporous Molecular Sieve Synthesized by Non-Hydrothermal Method in an Alkali-Free System

Influence of Aluminum Addition in the Framework of MCM-41 Mesoporous Molecular Sieve Synthesized by Non-Hydrothermal Method in an Alkali-Free System

Comparison of Lewis Acidity between Al-MCM-41 Pure Chemicals and Al-MCM-41 Synthesized from Bentonite

Heterogeneous catalyzed isomerization of turpentine oil by ordered mesoporous materials like M41S structures

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