Niobium oxide based materials as catalysts for acidic and partial oxidation type reactions

Vedrine, J. C.; Coudurier, G.; Ouqour, A.; Oliveira, P.G. Pries de; Volta, J.C.

doi:10.1016/0920-5861(95)00213-8

Cited by 49 publications

(25 citation statements)

References 23 publications

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“…Niobium (Nb)-based materials have been widely investigated in the past decades as promising and versatile heterogeneous catalysts [1][2][3][4]. In the class of niobium compounds, niobic acid (i.e., partly hydrated niobium oxide, Nb 2 O 5 •nH 2 O, hereafter labelled as NbO) [5,6] and niobium oxophosphate (NbOPO 4 •nH 2 O, hereafter labelled as NbP) [7,8] have aroused considerable interest as active phases, as supports, and also as promoters. In any case, these materials have consolidated their success mainly as solid acid catalysts [9,10] due to their acid strength (Hammett acidity function −8.2 < H o < −5.6 for NbO [4] and −8.2< H o < −3.0 for NbP [11]), co-presence of both Lewis and Brønsted acid sites (LAS and BAS, respectively), and capability to preserve Lewis acidity even in the presence of water.…”

Section: Introductionmentioning

confidence: 99%

Phosphate Enrichment of Niobium-Based Catalytic Surfaces in Relation to Reactions of Carbohydrate Biomass Conversion: The Case Studies of Inulin Hydrolysis and Fructose Dehydration

et al. 2021

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In this work, some physical mixtures of Nb2O5·nH2O and NbOPO4 were prepared to study the role of phosphate groups in the total acidity of samples and in two reactions involving carbohydrate biomass: hydrolysis of polyfructane and dehydration of fructose/glucose to 5-hydroxymethylfurfural (HMF). The acid and catalytic properties of the mixtures were dominated by the phosphate group enrichment. Lewis and Brønsted acid sites were detected by FT-IR experiments with pyridine adsorption/desorption under dry and wet conditions. Lewis acidity decreased with NbP in the composition, while total acidity of the samples, measured by titrations with phenylethylamine in cyclohexane (~3.5 μeq m−2) and water (~2.7 μeq m−2), maintained almost the same values. Inulin conversion took advantage of the presence of surfaces rich in Brønsted sites, and NbOPO4 showed the best hydrolysis activity with glucose/fructose formation. The catalyst with a more phosphated surface showed less deactivation during the dehydration of fructose/glucose into HMF.

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Section: Introductionmentioning

confidence: 99%

Phosphate Enrichment of Niobium-Based Catalytic Surfaces in Relation to Reactions of Carbohydrate Biomass Conversion: The Case Studies of Inulin Hydrolysis and Fructose Dehydration

et al. 2021

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“…It is interesting to note that the addition of ceria strongly decreased the surface 10 area of pure Nb 2 O 5 , although the herein obtained values are comparable to those reported in the literature for similar materials. Thus, Védrine et al 13 prepared niobic oxide with a surface area ranging from 140 to 35 m 2 g -1 by hydrolysis of NbCl 3 in aqueous solution with ammonia and calcination at different 15 temperatures(e.g. from 383 to 773 K).…”

Section: Resultsmentioning

confidence: 99%

Ce promoted Pd–Nb catalysts for γ-valerolactone ring-opening and hydrogenation

et al. 2012

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“…Wachs et al [39] and Védrine et al [40] have also reported the redox properties of niobium oxide. Meanwhile, Gallo et al [23] have reported that the oxidation activity of niobiumcontaining MCM-41 (Nb-MCM-41) in the epoxidation of alkene at higher temperature.…”

Section: Performance Of Catalystsmentioning

confidence: 99%

Characterization and Catalytic Performance of Niobic Acid Dispersed over Titanium Silicalite

Prasetyoko

Ramli

Endud

et al. 2008

Advances in Materials Science and Engineering

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Niobic acid, Nb 2 O 5 ·nH 2 O, has been supported on the titanium silicalite by impregnation method. The obtained materials were characterized by X-ray diffraction, infrared, and ultra-violet-visible diffuse reflectance spectroscopy, temperature programmed reduction, pyridine adsorption, and field emission scanning electron microscopy techniques. It was demonstrated that the tetrahedral titanium species still retained after impregnation of niobic acid. The results revealed that niobium species interacted with hydroxyl groups on the surface of TS-1. The niobium species in the catalysts are predominantly polymerized niobium oxides species or bulk niobium oxide with the octahedral structure. All catalysts showed both Brønsted and Lewis acid sites. The catalysts have been tested for epoxidation of 1-octene with aqueous hydrogen peroxide. It was found that the presence of niobic acid in the catalysts enhanced the rate of the formation of epoxide at the initial reaction time. Diol as a side product was also observed due to the acidic properties of the catalysts.

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Niobium oxide based materials as catalysts for acidic and partial oxidation type reactions

Cited by 49 publications

References 23 publications

Phosphate Enrichment of Niobium-Based Catalytic Surfaces in Relation to Reactions of Carbohydrate Biomass Conversion: The Case Studies of Inulin Hydrolysis and Fructose Dehydration

Phosphate Enrichment of Niobium-Based Catalytic Surfaces in Relation to Reactions of Carbohydrate Biomass Conversion: The Case Studies of Inulin Hydrolysis and Fructose Dehydration

Ce promoted Pd–Nb catalysts for γ-valerolactone ring-opening and hydrogenation

Characterization and Catalytic Performance of Niobic Acid Dispersed over Titanium Silicalite

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