Esterification of fatty acids with alcohols over niobium phosphate

Bassan, Iria A.L.; Nascimento, Danielle R.; Gil, Rosane A. S. San; Silva, Maria I. Pais da; Moreira, Carla R.; Gonzalez, Wilma A.; Faro, Arnaldo C.; Onfroy, Thomas; Lachter, Elizabeth R.

doi:10.1016/j.fuproc.2012.09.054

Cited by 69 publications

(49 citation statements)

References 39 publications

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“…The intensities of these bands have been calculated after deconvolution (see also Fig. S2 in Supporting information as an example of deconvolution) and the Brønsted-Lewis intensity ratio (B/L) results higher than 1, which is in agreement with reports from Bassan et al [18] claiming a prevailing Brønsted acidic character of this material. B/L ratio parameter, characterizing the acidic nature of the surface, has also been reported as directly related to catalyst selectivity to furfural production [28].…”

Section: Characterization Of Fresh Nbp Catalystsupporting

confidence: 88%

“…The broadening and shifting of the CC/CO stretching bands observed in the in situ IR experiments can be an indication of such an interaction. After this initial step, the activated reactants molecules can undergo the protonation of oxygen atoms from the acidic P OH, mainly, resulting in carbocations formation, in agreement with the mechanism proposed by Bassan et al for the esterification of fatty acids [18]. Likely, water in the reaction environment favors the desorption of furfural, that can be detected either as adsorbed species (see the carbonyl band in Fig.…”

Section: Working Surfacesupporting

confidence: 86%

“…FT IR spectroscopy has also been applied, together with microcalorimetry, to analyze adsorption of probe molecule such as methanol, dimethylether and ammonia over NbOPO 4 catalyst, the strong interaction of such probe molecules evidencing that NbOPO 4 is more acidic than pure Niobia [2]. Pyridine adsorption/desorption experiments allow quantification of Brønsted and Lewis acidic sites [17,18], however its diagnostic bands fall in a spectral region which can be strongly perturbed by the signal of adsorbed organic species, i.e., heavy reaction by products over the spent catalyst. On the other side, to the best of our knowledge, pivalonitrile adsorption to characterize NbP surface, has not yet been reported, in spite of several advantages shown by this probe molecule, as recently underlined by several authors [19].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

NbP catalyst for furfural production: FT IR studies of surface properties

Gómez-Bernal

Galletti

Garbarino

et al. 2015

Applied Catalysis A: General

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Section: Characterization Of Fresh Nbp Catalystsupporting

confidence: 88%

Section: Working Surfacesupporting

confidence: 86%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

NbP catalyst for furfural production: FT IR studies of surface properties

Gómez-Bernal

Galletti

Garbarino

et al. 2015

Applied Catalysis A: General

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“…It was also suggested that the conversion of acid obtained in the esterification with alcohol depends on the alcohol nucleophilicity where the longer carbon chain length leads to the less nucleophilicity of alcohol, hence reduce the ability to donate an electron pair [30]. Steric effect also plays an important factor in determining the oleic acid conversion.…”

Section: Effects Of Alcoholsmentioning

confidence: 99%

Esterification of oleic acid with alcohols over Cu-MMT K10 and Fe-MMT K10 as acid catalysts

Harun

Jihadi

Ramli

et al. 2018

AIP Conference Proceedings

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Abstract. The esterification of free fatty acids with alcohols using montmorillonite (MMT) clay as heterogeneous catalyst is one of the methods to produce fatty acid alkyl ester that can be used as alternative renewable biofuels. However, the unmodified MMT gives low conversion of free fatty due to the limitation of acid sites in the clay structure. This work focuses on preparation of an environmental friendly catalyst from montmorillonite K10 (MMT K10) clay catalyst for the esterification of oleic acid with various alcohols. Esterification of oleic acid with alcohols has been carried out in the presence of metal exchanged MMT K10 (M-MMT K10; M = Fe 3+ and Cu 2+ ). The concentrations of both Fe 3+ and Cu 2+ precursors were varied at 1 M and 4 M. The effect of different alcohols used, molar ratio of reactants and catalyst loading on the esterification reaction was investigated. Among the exchanged clay catalysts, 4 M Fe-MMT K10 was found to be more active for the esterification of oleic acid with methanol. The maximum oleic acid conversion (ca. 68.5%) was achieved after 3 hours of reaction at the reaction temperature of 60 o C with molar ratio of methanol to oleic acid of 10:1 and catalyst loading of 5 wt% relative to the mass of oleic acid. The catalytic activity was found to be directly related to the amount of cation used in the modification step and Brønsted acidity of metal exchanged MMT K10 clay catalyst.

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“…Recently, NbPO4 has been employed as an heterogeneous catalyst for the dehydration of fructose, [14] the esterification of fatty acids, [15] the oxidation of benzyl alcohols [16] and the benzylation of anisoles. [17] Due to its considerable Brønsted acidity (H0 ~ -8.6 to -5.6) [18] and its heterogeneous nature, NbPO4 warrants investigation for protection-deprotection of alcohols.…”

Section: Introductionmentioning

confidence: 99%

Tetrahydropyranyl protection and deprotection of alcohols using a niobium-based Brønsted acid catalyst

et al. 2016

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Crites, CL.; Lima, FM.; Marín García, ML.; Netto Ferreira, JC.; Impellizzeri, S.; HallettTapley, GL.; Scaiano, JC. (2016) Abstract. Niobium phosphate (NbPO4) was used as a heterogeneous catalyst in the protection of a series of aliphatic alcohols as tetrahydropyranyl (THP) derivatives.Protection of primary alcohols using this material with strong Brønsted acid sites was achieved in good yields (75-94%), while moderate values were obtained in the protection of secondary and tertiary alcohols (50-84%), largely dependent on the steric hindrance in the proximity of the hydroxyl moiety. NbPO4 also catalyzed deprotection of THP ethers derived from primary alcohols and phenol with moderate yields (65-99%).2

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Esterification of fatty acids with alcohols over niobium phosphate

Cited by 69 publications

References 39 publications

NbP catalyst for furfural production: FT IR studies of surface properties

NbP catalyst for furfural production: FT IR studies of surface properties

Esterification of oleic acid with alcohols over Cu-MMT K10 and Fe-MMT K10 as acid catalysts

Tetrahydropyranyl protection and deprotection of alcohols using a niobium-based Brønsted acid catalyst

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