Structure–property relationships of some amorphous and crystalline aluminophosphates

Babu, G.P.; Ganguli, P.; Rockliffe, Jeffrey W.; Smith, Edward G.

doi:10.1039/jm9940400331

Cited by 13 publications

(13 citation statements)

References 27 publications

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“…The structural and acidic properties of amorphous AlP can be fine-tuned by controlling the preparation conditions and also by adding selected transition metals during the synthesis. The addition of a transition metal during synthesis can lead to the formation of Lewis and Brönsted acid sites along with basic sites [4]. These acidic and basic sites along with redox properties suggest the possibility to design unique bifunctional catalysts.…”

Section: Introductionmentioning

confidence: 99%

Amorphous metal-aluminophosphate catalysts for aldol condensation of n-heptanal and benzaldehyde to jasminaldehyde

Hamza¹,

Nagaraju²

2015

Chinese Journal of Catalysis

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Section: Introductionmentioning

confidence: 99%

Amorphous metal-aluminophosphate catalysts for aldol condensation of n-heptanal and benzaldehyde to jasminaldehyde

Hamza¹,

Nagaraju²

2015

Chinese Journal of Catalysis

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“…Amorphous aluminophosphates or AlPO systems, formally AlPO 4 −Al 2 O 3 , have been shown to be highly efficient catalysts in a wide variety of processes including dehydrogenation, cracking, and isomerization reactions, and as support for other catalytic systems such as oxides − or metals .…”

Section: Introductionmentioning

confidence: 99%

Geometric and Electronic Structure of Amorphous Aluminophosphates. Ab Initio and Experimental Studies

Márquez¹,

Oviedo²,

Sanz³

et al. 1997

J. Phys. Chem. B

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A combination of experimental (diffuse reflectance infrared Fourier transform spectroscopy, DRIFTS, and X-ray photoelectron spectroscopy, XPS) and ab initio studies of model clusters is used to understand the geometric and electronic structure of aluminophosphate (AlPO) systems used as catalytic materials. The presence of an intense IR band in the DRIFTS spectra, around 1300 cm-1, together with literature data suggested to represent the system using cluster models based on metaphosphate-like structures. By varying the P/Al atomic ratio the basic features of AlPO4−Al2O3 catalysts are modeled. The calculated geometrical parameters (bond distances and associated stretch force constants) are discussed in relation to the structure of the catalyst and, despite the inherent approximations in modeling solids with cluster models, fits quite well-the experimental X-ray data for aluminum metaphosphate. The computed ionization potentials (IP), OKVV transitions, and IR spectra are in reasonable agreement with experimental data. The observed trends in XPS, continuous decrease of Al2p, and P2p and O1s binding energies on decreasing the P/Al ratio are explained in terms of the alteration of the electronic density of the O atoms induced by the presence of Al as second neighbor of the P atom. A similar effect of this second neighbor lets us explain the modification of the OKVV and DRIFTS data. As a result of these studies a model for the short-range structure of amorphous AlPO systems is proposed based on metaphosphate anions conected by layers rich in aluminum with γ-Al2O3-like structure.

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“…Taking into account the amorphous and hygroscopic behaviors of the powders, peaks at -10 and 10 ppm are linked to aluminum in octahedral site and 5-fold coordinated sites respectively. Indeed, structural disorder [36,40] and/orthe presence of OH groups [37,38] Al and 31 P towards higher chemical shifts.…”

Section: Nmr Characterizationsmentioning

confidence: 99%

“…NMR 27 Al spectrum of AlPO 4 displays a major peak at 40 ppm and a second one less intensive at -10 ppm, as well as a shoulder at 10 ppm ( Figure 2). According to different authors, the main peak is attributed to aluminum in tetrahedral environment [36][37][38][39][40]. Taking into account the amorphous and hygroscopic behaviors of the powders, peaks at -10 and 10 ppm are linked to aluminum in octahedral site and 5-fold coordinated sites respectively.…”

Section: Nmr Characterizationsmentioning

confidence: 99%

Transesterification of vegetable oils by AlPOxNy heterogeneous catalysts

Tessier

Ray

Cheviré

et al. 2016

Applied Catalysis B: Environmental

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Structure–property relationships of some amorphous and crystalline aluminophosphates

Cited by 13 publications

References 27 publications

Amorphous metal-aluminophosphate catalysts for aldol condensation of n-heptanal and benzaldehyde to jasminaldehyde

Amorphous metal-aluminophosphate catalysts for aldol condensation of n-heptanal and benzaldehyde to jasminaldehyde

Geometric and Electronic Structure of Amorphous Aluminophosphates. Ab Initio and Experimental Studies

Transesterification of vegetable oils by AlPOxNy heterogeneous catalysts

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