Establishing the role of Brønsted acidity and porosity for the catalytic etherification of glycerol with tert-butanol by modifying zeolites

González, María Dolores López; Cesteros, Yolanda; Salagre, Pilar

doi:10.1016/j.apcata.2012.10.028

Cited by 70 publications

(33 citation statements)

References 39 publications

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“…The reaction pattern considered when tert-butylation of glycerol is carried out in presence of an O-alkylating agent, such as isobutylene (IB), or tert-butyl alcohol (TBA) [7][8][9][10][11][12][13][14][15] is shown in Scheme 3.…”

Section: Resultsmentioning

confidence: 99%

“…Anyhow, glycerol etherification reaction in presence of linear alcohols is not widely studied since it is thermodynamically much more difficult than in presence of tert-butyl alcohol. In addition, in presence of an alcohol, water is formed as by-product with consequent negative effects on catalytic activity and selectivity [13][14][15]. The water formed in each step in fact competes with reactants on the active site adsorption, preventing the total glycerol conversion and the formation of desired poly-substituted ethers [19].…”

Section: Introductionmentioning

confidence: 98%

“…These compounds could led to the formation of undesirable deposits during combustion in the diesel engine, therefore they must be removed from the ethers mixture before its use as additive. The use of a liquid reagent instead of gaseous IB could be favourable since it can act both as reactant and solvent allowing to overcome the technological problems arising from the need to operate with solvents to dissolve glycerol or the need to use pressure to keep IB in the liquid phase [11][12][13][14][15]. On this account, to date, the catalytic etherification of glycerol has been studied starting from tert-butyl alcohol (TBA), which is a by-product of polypropylene production.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Batch reactor coupled with water permselective membrane: Study of glycerol etherification reaction with butanol

Cannilla

Bonura

Frusteri³

et al. 2015

Chemical Engineering Journal

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Batch reactor coupled with water permselective membrane: Study of glycerol etherification reaction with butanol

Cannilla

Bonura

Frusteri³

et al. 2015

Chemical Engineering Journal

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“…[65][66][67][68][69][70][71][72] For example, Kuwahara et al designed a new class of heterogeneous catalytic systems utilizing this effect: cation-π interactions (π from potential reactive molecules) in microporous titanosilicate molecular sieves for cyclohexene epoxidation [39]. Possibly the heavier alkali metal cations (K + , Rb + , and Cs + ) have an increased interaction with the cyclohexene molecules as a result of a weak cation-π interaction, which results in an enhancement of their catalytic activity and selectivity for epoxidation.…”

mentioning

confidence: 99%

Modification of acid sites in ZSM-5 by ion-exchange: An in-situ FTIR study

Wu¹,

Weitz

2014

Applied Surface Science

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A study of the acid sites in M n+ -ZSM-5 zeolites (M n+ = H + , Al 3+ , Ca 2+ , and Ba 2+ ), synthesized by ion-exchange from the NH 4 + form, has been carried out using X-ray diffraction, 27 Al MAS NMR, and in-situ FTIR spectroscopy. X-ray diffraction data indicate that the crystalline structure of ZSM-5 is maintained on ion-exchange. 27 Al MAS NMR spectroscopy confirms that Lewis acid sites in all of the M n+ -ZSM-5 zeolites are mainly located on the tetrahedral aluminum atoms in the zeolite framework. However, octahedral extra-framework aluminum is another source of Lewis acid sites in H + -ZSM-5 and Al 3+ -ZSM-5. Brønsted acid sites are identified as originating from the hydroxyl groups that bridge Al and Si atoms. The acid sites in M n+ -ZSM-5 have been characterized by in-situ FTIR spectroscopy with pyridine as the probe molecule. FTIR spectroscopy demonstrated that the number of accessible acid sites and ratio of Lewis to Brønsted acid sites in M n+ -ZSM-5 can be effectively modified by ion-exchange. The number of acid sites in M n+ -ZSM-5 increases in the same order as the acidity of cations with Ba 2+ < Ca 2+ < NH 4 + < Al 3+ < H + . Though the strength of both Lewis and Brønsted acid sites is virtually identical for all M n+ -ZSM-5 zeolites, the ratio of Brønsted to Lewis acid sites varies as a result of the loaded cation. In addition, modification of acid sites in M n+ -ZMS-5 by loading different cations is discussed in terms of the accessibility of the surface of the zeolite channels and the reactivity of the cations with Brønsted acid hydroxyls. Weconclude that larger cations can effectively constrict the zeolite channels and impede the ability of pyridine to access acid sites on the surface of the channels.

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“…Selective etherification of glycerol into monoalkyl glycerol ethers, which exhibit a wide spectrum of biological activities such as anti-inflammatory, anti-bacterial, antifungal, immunological stimulation and anti-tumour properties. 28 Another important derivative of ME, dioxolanes, is also used as co-fuels for the diesel fraction. 20 The main routes proposed for the synthesis of GC are: (i) reaction of glycerol with phosgene, 29 (ii) transesterification of glycerol with dimethyl carbonate [30][31][32] or ethylene carbonate, 33 (iii) reaction of glycerol with urea, [33][34][35][36] and (iv) carbonation of glycerol with carbon dioxide.…”

Section: Introductionmentioning

confidence: 99%

Understanding the surface and structural characteristics of tungsten oxide supported on tin oxide catalysts for the conversion of glycerol

et al. 2015

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Catalysts with varying WO 3 content on SnO 2 were prepared and characterized by X-ray diffraction, in situ Raman spectroscopy, X-ray photoelectron spectroscopy and temperature programmed desorption of NH 3 . In situ Raman analysis reveals the presence isolated monomers and polymeric species of WO 3 . These catalysts were evaluated for the conversion of glycerol into value added chemicals. Etherification of glycerol with tertiary butanol and preparation of glycerol carbonate from glycerol and urea are studied over these catalysts. The catalytic activity results suggest that the glycerol conversion and selectivity depends on the morphology of WO 3 which in turn is related to its content in the catalyst. The catalysts with 5 wt.% of WO 3 on SnO 2 resulted in high dispersion with larger number of strong acidic sites. The selectivity in the glycerol etherification is related to the nature of the catalyst and reaction time. These catalysts also exhibited high activity for synthesis of glycerol carbonate. The effect of various reaction parameters was studied to optimize the reaction conditions. The catalysts also exhibited consistent activity upon reuse.

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Establishing the role of Brønsted acidity and porosity for the catalytic etherification of glycerol with tert-butanol by modifying zeolites

Cited by 70 publications

References 39 publications

Batch reactor coupled with water permselective membrane: Study of glycerol etherification reaction with butanol

Batch reactor coupled with water permselective membrane: Study of glycerol etherification reaction with butanol

Modification of acid sites in ZSM-5 by ion-exchange: An in-situ FTIR study

Understanding the surface and structural characteristics of tungsten oxide supported on tin oxide catalysts for the conversion of glycerol

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