Acid-Modified Clays for the Catalytic Obtention of 5-Hydroxymethylfurfural from Glucose

Abstract

5-hydroxymethylfurfural (5-HMF) is an important platform molecule for the synthesis of high-added value products. Several synthesized clay materials, such as mesoporous hectorite and fluorohectorite, in addition to commercial montmorillonite K-10, have been acid modified by different methodologies to be applied as catalysts for the obtention of 5-HMF from glucose. The effects of the Brønsted and/or Lewis acidity, the reaction temperature and time, and the catalyst/glucose ratio on the conversion but especially on the selectivity to 5-HMF have been studied. By comparing the synthesized clays, the best selectivity to 5-HMF (36%) was obtained at 140 °C for 4 h with H-fluorohectorite because of the presence of strong Brønsted acid sites, although its conversion was the lowest (33%) due to its low amounts of Lewis acid sites. Different strategies, such as physical mixtures of montmorillonite K10, which contains high amounts of Lewis acid centers, with Amberlyst-15, which has high amounts of Brønsted acid sites, or the incorporation of rhenium compounds, were carried out. The best selectivity to 5-HMF (62%) was achieved with a mixture of 44 wt % Amberlyst-15 and 56 wt % of montmorillonite K10 for a 56% of conversion at 140 °C for 4 h. This proportion optimized the amount of Brønsted and Lewis acid sites in the catalyst under these reaction conditions.

Nanoparticles for the synthesis of bio‐based chemical 5‐Hydroxymethyl furfural from agricultural waste and biomass‐derived carbohydrates‐A review

“…8 The various heterogeneous catalysta used for HMF synthesis include ion exchange resin, 9 modified Amberlyst-15, 10 zeolites, [11][12][13] heteropoly acids [14][15][16] and modified clays. [17][18][19][20] The main benefit of heterogeneous catalysts is that they are in the solid phase, and are simple to recycle from the gas and/or wileyonlinelibrary.com/jctb liquid reactants and products. 21 Generally, a heterogeneous catalyst is a highly porous material.…”

“…Somorjai's review determined that achieving 100% selectivity of the intended product – that is, ensuring that no undesirable byproduct is produced – is a top priority for researchers studying catalysis, and that it is necessary to advance catalysis science and engineering to provide molecular control over the shape, size and position of metallic nanoparticles (NPs) as well as catalytic promoters 8 . The various heterogeneous catalysta used for HMF synthesis include ion exchange resin, 9 modified Amberlyst‐15, 10 zeolites, 11‐13 heteropoly acids 14‐16 and modified clays 17‐20 …”

A Themed Issue in Honor of Prof. Dr. Vicente Rives

“…This Special Issue has received eighteen contributions, six review papers [1][2][3][4][5][6], and twelve research papers [7][8][9][10][11][12][13][14][15][16][17][18]. Most of the papers originated from groups who have previously worked with Prof. Rives, but five of the contributions came from authors who had not previously worked with him [6,7,13,17,18]. The materials most studied by Prof. Rives throughout his career were LDHs.…”

“…Therefore, it was not surprising that these materials were the basis of eight of the papers published in this Special Issue [2][3][4]10,11,[15][16][17]. Other materials included Ni-based catalysts [1], g-C 3 N 4 [5], mesoporous silica [6], MOFs [7], carbons [8,9], AlPO 4 [12], acid-modified clays [13], and porous aluminosilicates [17]. Finally, one of the papers was devoted to the study of cultural heritage conservation [14].…”

“…Labajos et al explored new routes for the preparation of LDHs using various amines in the synthesis process [10], while Nebot-Díaz et al used LDH as precursors of nanoparticle black pigments for the ceramic industry [11]. Ciuffi et al used Zn-AlPO 4 as photocatalysts for the degradation of fipronil [12], and Cesteros et al used acid-modified clays as catalysts for the preparation of 5-hydroxymethylfurfural from glucose [13]. Vicente et al prepared Fe-doped hydrocalumites (a type of LDH) from aluminum slags and used them for the photodegradation of ibuprofen [15].…”