Aluminophosphates Oxynitrides as Base Catalysts: Nature of the Base Sites and Their Catalytic Implications

Climent, María J.; Corma, Avelino; Fornés, Vicente; Frau, A.; Guil-López, R.; Iborra, Sara; Primo, Jaime

doi:10.1006/jcat.1996.0340

Cited by 106 publications

(72 citation statements)

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“…ÞÞ CHEMCATCHEM FULL PAPERS www.chemcatchem.org metal oxides, such as high-surface-area magnesium oxides, [19] layered magnesium aluminates [20] that bear strong Lewis basic sites, nitrated aluminum phosphates (ALPONs) [21] with medium basic strength sites, and alkali cation-exchanged zeolites [22] with weak basic strength sites, have been utilized widely to promote base-catalyzed processes.…”

Section: Catalytic Cascade Applicationsmentioning

confidence: 99%

Zirconium Materials from Mixed Dicarboxylate Linkers: Enhancing the Stability for Catalytic Applications

et al. 2014

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We report the synthesis of two series of zirconium‐based metal–organic frameworks from solutions composed of a mixed‐ligand system (naphthalene dicarboxylic acid/4‐amino‐2,6‐naphthalenedicarboxylic acid or [1,1′‐biphenyl]‐4,4′‐dicarboxylic acid (BPDC)/2‐amino‐[1,1′‐biphenyl]‐4,4′‐dicarboxylic acid). Materials synthesized with low loadings of functionalized linkers exhibit higher long‐term chemical stability and similarly high thermal stability relative to those with 100 % amino linkers. These materials and their corresponding rhodium derivatives prove excellent catalysts in one‐pot reactions. Moreover, the recycling experiments demonstrate an interesting prospect for the long‐term reusability of these catalysts.

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Section: Catalytic Cascade Applicationsmentioning

confidence: 99%

Zirconium Materials from Mixed Dicarboxylate Linkers: Enhancing the Stability for Catalytic Applications

et al. 2014

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“…It will be shown that, when the number of acid sites of the aluminum phosphate is systematically reduced while increasing the number and strength of the basic ones (nitrurated aluminum phosphate, ALPON), [7,8] both activity and selectivity decrease. It will be shown that the bifunctional system is able to perform the synthesis of jasminaldehyde at much higher rates than either acid (silicates) or basic (MgO, KF/Al 2 O 3 , ALPON) catalysts.…”

Section: Full Papersmentioning

confidence: 99%

Aldol Condensations on Solid Catalysts: A Cooperative Effect between Weak Acid and Base Sites

Climent

Corma

Fornés

et al. 2002

Advanced Synthesis & Catalysis

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126

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An amorphous aluminophosphate (ALPO) catalyst containing weak acid and base centers can carry out the aldol condensation of heptanal with benzaldehyde at much higher rates and selectivities than conventional solid acid (amorphous or crystalline aluminosilicates) or base catalysts (MgO, hydrotalcites, KF/Al2O3, nitrurated ALPO). With the weak acid‐base catalyst, the reaction occurs through a bifunctional acid‐base mechanism that involves the activation of benzaldehyde, by protonation‐polarization of the carbonyl group on the acid sites, and the attack of the enolate heptanal intermediate generated on the basic sites. With this type of bifunctional acid‐base catalyst, compounds with weak basicities are already able to undergo the reaction with a much higher selectivity than those obtained on stronger acid or base catalysts.

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“…Other research groups confirmed the suitability of zeolite catalysts with the MFI structure, such as silicalite-1 [3], BZSM-5 [4] or titanium silicalite-1 [5], for the rearrangement of cyclohexanone oxime. There is general agreement that the amount of heteroatoms (Al, B, Ti) isomorphously substituted in the zeolite framework and the textural properties of the zeolite, e.g., its crystallite size and crystallinity, are of major importance.…”

Section: Discussionmentioning

confidence: 94%

“…For example, the reaction of silicon dioxide with ammonia at 1000 C results in the formation of silicon oxynitride (Si 2 N 2 O) [2,3]. The treatment of amorphous aluminophosphates with ammonia leads to basic catalysts, which can be described as aluminophosphate oxynitrides [4,5].…”

Section: Introductionmentioning

confidence: 99%

Porous Silicon Nitride Materials as Basic Catalysts

Hullmann¹,

Wendt²,

Ziegenbalg³

2001

Chem. Eng. Technol.

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Investigations were conducted to test the use of amorphous silicon nitride as a basic catalyst. Silicon nitride powders characterized by a high specific surface area were prepared by gas‐phase ammonolysis of tetrachlorosilane. The Knoevenagel condensation of benzaldehyde and malonitrile served as a test reaction to characterize the catalytic properties of the materials. It was found that favorable synthesis conditions result in powders showing a stronger catalytic activity than high surface magnesium oxide. However, a disadvantage is the sensitivity of the amorphous silicon nitride against water.

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Aluminophosphates Oxynitrides as Base Catalysts: Nature of the Base Sites and Their Catalytic Implications

Cited by 106 publications

References 0 publications

Zirconium Materials from Mixed Dicarboxylate Linkers: Enhancing the Stability for Catalytic Applications

Zirconium Materials from Mixed Dicarboxylate Linkers: Enhancing the Stability for Catalytic Applications

Aldol Condensations on Solid Catalysts: A Cooperative Effect between Weak Acid and Base Sites

Porous Silicon Nitride Materials as Basic Catalysts

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