Tailoring the acid strength of microporous silicoaluminophosphates through the use of mixtures of templates: Control of the silicon incorporation mechanism

Gómez‐Hortigüela, Luis; Márquez‐Álvarez, Carlos; Grande-Casas, Marisol; García, Raquel; Pérez‐Pariente, Joaquín

doi:10.1016/j.micromeso.2009.01.034

Cited by 23 publications

(21 citation statements)

References 25 publications

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“…Many attempts (synthesis strategies) have been performed to improve Si incorporation as well as Si distribution in order to obtain a good compromise between acidity properties and catalytic performances. One can cite, for example, the use of different reagent sources [11][12][13] and particular synthesis methods like biphasic systems [5,14,15] and multiple ''dual'' templates utilization [16], with some authors arguing for a cooperative effect or a difference of hydrophilic/hydrophobic character between the two templates [17][18][19]. This study deals with the catalytic properties of platinum based SAPO-11 material, synthesized by means of two co-templates, methylamine (MA) and dipropylamine (DPA), which is the usual template currently employed for the AEL structure.…”

Section: Introductionmentioning

confidence: 99%

Hydroisomerization of n-decane over SAPO-11 catalysts synthesized with methylamine as co-template

Bértolo¹,

Fernandes²,

Ribeiro³

et al. 2009

Reac Kinet Mech Cat

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The present work deals with preliminary studies concerning a new synthesis approach to prepare SAPO materials with AEL structure and evaluate their catalytic behavior in the hydroisomerization of long paraffins. The new SAPO-11 catalysts were synthesized with the help of a small amine (methylamine, MA) added during the preparation of the initial gel. As MA incorporates into the structure of the final materials, it contributes, together with DPA (dipropylamine), to an increase in Si incorporation as isolated species, which results in Bronsted acid sites. Thus, this new and original synthesis strategy allows to obtain materials with enhanced Bronsted acidity when compared with free MA materials. The catalysts were tested in n-decane hydroisomerization (n-decane was used as a model molecule) and confirmed the effect of MA on the acidic properties of the catalysts. The samples synthesized with MA present a higher number of acid sites that increase the catalytic conversion but have a negative effect in the isomerization selectivity, i.e. a more significant amount of cracking products is formed.

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Section: Introductionmentioning

confidence: 99%

Hydroisomerization of n-decane over SAPO-11 catalysts synthesized with methylamine as co-template

Bértolo¹,

Fernandes²,

Ribeiro³

et al. 2009

Reac Kinet Mech Cat

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“…This sample is reported to contain higher number of Brønsted acid sites but weaker and more hydrophilic [11]. This mild acidity could be responsible for a better performance of this catalyst.…”

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confidence: 87%

“…SAPO-5 and MeAPO-5 samples were kindly donated by the authors [11,12] from the Institute of Catalysis and Petroleochemistry, CSIC (Madrid, Spain). Each microporous material contains water molecules adsorbed on the surface, and is prepared in the presence of structure directing agent (SDA).…”

Section: Synthesis and Activation Of Sapo-5 And Meapo-5 Catalystsmentioning

confidence: 99%

“…Zeotypes are aluminophosphate based crystalline microporous solids whose acidity can be controlled from the synthesis conditions. Silicoaluminophosphates (SAPOs) and aluminophosphates (MeAPOs) can be designed by different mechanisms of silicon and metal insertion to obtain tuned acidity including both Lewis and Brønsted acid sites [11,12]. Among the zeolitic materials reportred in the literature, mordenite zeolites with moderate acidity have shown promising fructose conversion with maximum selectivity to 5-HMF (90%) [13].…”

Section: Introductionmentioning

confidence: 99%

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Conversion of glucose into platform chemicals using aluminophosphates (SAPO-5 and MeAPO-5) in [BMIM]Cl ionic liquid

Ayele¹,

Dadi²,

Mamo³

et al. 2014

Bull. Chem. Soc. Eth.

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ABSTRACT. The conversion of glucose into platform chemicals such as 5-hydroxymethylfurfural, levulinic acid and formic acid has been investigated using two aluminophosphate based zeotypes (SAPO-5 and MeAPO-5) catalysts in 1-butyl-3-methylimidazolium chloride [BMIM]Cl ionic liquid as a reaction medium. The silico aluminophosphates (SAPO-5) and metal aluminophosphates (MeAPO-5) were designed and chosen for their tunable amount and strength of acid sites. The dehydration of glucose using each catalyst gave more than 90% glucose conversion. Among all the catalysts tested, the most hydrophilic SAPO-5 (1.5T) results in a better 5-HMF yield of 8% at 100 °C and 6 h reaction time. Contrary to this, the more hydrophobic SAPO-5 gives higher yield of levulinic acid and formic acid and no 5-HMF yield at this particular reaction time. In general, despite the higher glucose conversion attained by these aluminophosphate based catalysts, the lower yield obtained by these materials can be attributed to the type of acidity and the incompatibility of the pore diameter of the AFI channels of the catalysts and the desired products.

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“…[18,20] Gόmez-Hortigüela et al [21] reported about the influence of the template mixture on the incorporation of Si into the framework. Using a mixture of triethylamine (TEA) and benzylpyrrolidine (BP) as templates leads to the formation of large Si islands, while using exclusively TEA as template enhances the formation of isolated Si(OAl) 4 species.…”

Section: Introductionmentioning

confidence: 99%

Impact of Conventional and Microwave Heating on SAPO‐5 Formation and Brønsted Acidic Properties

Dang¹,

Hoang

Schneider

et al. 2014

Zeitschrift anorg allge chemie

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Abstract. The hydrothermal crystallization of SAPO-5 molecular sieves with Si mole ratios in the range of 0.05 to 0.13 was performed by either conventional or microwave heating to compare the influence of these two techniques on the isomorphous substitution of phosphorus by silicon atoms in the aluminophosphate framework. An extensive characterization of the obtained silicoaluminophosphates by ICP-OES, SEM, XRD, TPDA, and MAS NMR spectroscopy indicated that conventional heating (drying oven) led to a better crystallinity and a higher content of isolated framework silicon atoms than microwave heating.

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Tailoring the acid strength of microporous silicoaluminophosphates through the use of mixtures of templates: Control of the silicon incorporation mechanism

Cited by 23 publications

References 25 publications

Hydroisomerization of n-decane over SAPO-11 catalysts synthesized with methylamine as co-template

Hydroisomerization of n-decane over SAPO-11 catalysts synthesized with methylamine as co-template

Conversion of glucose into platform chemicals using aluminophosphates (SAPO-5 and MeAPO-5) in [BMIM]Cl ionic liquid

Impact of Conventional and Microwave Heating on SAPO‐5 Formation and Brønsted Acidic Properties

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