Synthesis of amorphous aluminosilicates by grafting: Tuning the building and final structure of the deposit by selecting the appropriate synthesis conditions

Caillot, M.; Chaumonnot, Alexandra; Digne, Mathieu; Poleunis, Claude; Debecker, Damien P.; Bokhoven, Jeroen A. van

doi:10.1016/j.micromeso.2013.10.032

Cited by 35 publications

(118 citation statements)

References 38 publications

Supporting

Mentioning

109

Contrasting

Order By: Relevance

“…Mesoporous monomodal aluminosilicate carriers were obtained by grafting silica on the alumina surface as described elsewhere [44,45] (see Table 1). Trilobic alumina extrudes obtained by copreciptation of aluminum sulfate and sodium aluminate were used.…”

Section: Alumina Grafting (Carrier Preparation)mentioning

confidence: 99%

Effect of acidity, hydrogenating phases and texture properties of catalysts on the evolution of asphaltenes structures during reside hydroconversion

2015

View full text Add to dashboard Cite

Section: Alumina Grafting (Carrier Preparation)mentioning

confidence: 99%

Effect of acidity, hydrogenating phases and texture properties of catalysts on the evolution of asphaltenes structures during reside hydroconversion

2015

View full text Add to dashboard Cite

“…In comparison, overcoating with SiO 2 by solgel chemistry is low-cost and easy to scale up. Although the degree of control does not match ALD's, the overcoat's thickness can be kinetically controlled within a few nm due to the low reactivity of siloxide precursors [14,15]. The utility of silica overcoating is nevertheless limited by silica's low stability in high temperature liquid-phase conditions, which lead to rapid structural collapse [16].…”

Section: Introductionmentioning

confidence: 99%

Catalyst stabilization by stoichiometrically limited layer-by-layer overcoating in liquid media

Héroguel

Monnier

Brown

et al. 2017

Applied Catalysis B: Environmental

View full text Add to dashboard Cite

a b s t r a c tThe use of metal oxide overcoats over supported nanoparticle catalysts has recently led to impressive improvements in catalyst stability and selectivity. The deposition of alumina is especially important for renewable catalysis due to its robustness in liquid-phase conditions. However, there are limited reports of work on alumina deposition and stabilization that goes beyond atomic layer deposition (ALD). Here, we present a layer-by-layer deposition technique for the controlled formation of conformal alumina overcoats in the liquid phase. This technique is easy to perform in common wet chemistry conditions. Alternated exposure of the substrate to stoichiometric amounts of aluminum alkoxide and water in liquidphase conditions leads to the formation of a porous overcoat that was easily tunable by varying synthesis parameters. The deposition of 60 Al 2 O 3 layers onto Al 2 O 3 -supported copper nanoparticles suppressed irreversible deactivation during the liquid-phase hydrogenation of furfural -a key biomass-derived platform molecule. The porous overcoat leads to highly accessible metal sites, which significantly reduces the partial site blocking observed in equivalent overcoats formed by ALD. We suggest that the ease of scalability and the high degree of control over the overcoat's properties during liquid-phase synthesis could facilitate the development of new catalyst overcoating applications.

show abstract

“…Amorphous aluminosilicate catalysts have been used industrially on al arge scale for almost ac entury.H owever,t he influence of the pH on the alumination of silica in aqueous solutions has remainedl argely unclear.H erein, room temperature aluminations of different mesoporousa morphous silicas (fumeds ilica, dried silica gel, SBA-15, MCM-41, and COK-12) with aqueous solutionso fv ariousp H (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13) are explored. The aqueous solutions are prepared using different aluminums ources( Al(NO 3 ) 3 or NaAlO 2 )and alkaline additives (NaOH or NH 4 OH).…”

Section: A Ndmentioning

confidence: 99%

“…[2][3][4][5] The advantage of ASA over (purely Lewis acidic) alumina is that Brønsted acid sites are formed if monomeric aluminumi s incorporated in the silica framework with at etrahedral coordination (isomorphous substitution). [8][9][10][11][12][13][14][15][16] Not only the relative quantity of silica and alumina can vary strongly,b ut also their distribution (zoning, gradients, etc. [8][9][10][11][12][13][14][15][16] Not only the relative quantity of silica and alumina can vary strongly,b ut also their distribution (zoning, gradients, etc.…”

Section: Introductionmentioning

confidence: 99%

“…[8][9][10][11][12][13][14][15][16] One of the most used (and commerciallya ttractive) methods may be the deposition of Al by subjecting silica to Al-containinga queous solutions, taking advantage of the hydrolysis-condensation behavior of Al 3 + ions in water.T he latter is typicallyp erformed by using various Al salts such as Al 2 (SO 4 ) 3 ,A l(NO 3 ) 3 [8][9][10][11][12][13][14][15][16] One of the most used (and commerciallya ttractive) methods may be the deposition of Al by subjecting silica to Al-containinga queous solutions, taking advantage of the hydrolysis-condensation behavior of Al 3 + ions in water.T he latter is typicallyp erformed by using various Al salts such as Al 2 (SO 4 ) 3 ,A l(NO 3 ) 3 …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Synthetic and Catalytic Potential of Amorphous Mesoporous Aluminosilicates Prepared by Postsynthetic Aluminations of Silica in Aqueous Media

et al. 2018

View full text Add to dashboard Cite

Amorphous aluminosilicate catalysts have been used industrially on a large scale for almost a century. However, the influence of the pH on the alumination of silica in aqueous solutions has remained largely unclear. Herein, room temperature aluminations of different mesoporous amorphous silicas (fumed silica, dried silica gel, SBA‐15, MCM‐41, and COK‐12) with aqueous solutions of various pH (3–13) are explored. The aqueous solutions are prepared using different aluminum sources (Al(NO3)3 or NaAlO2) and alkaline additives (NaOH or NH4OH). The decoupling of pH and Al source using alkaline additives results in a vast experimental potential to prepare unique aluminosilicates, whereby an important role is played by the pH development during the treatment. The bulk and surface composition, acidity, aluminum coordination, morphology, hydrothermal stability, and porosity of the obtained materials are characterized. Optimal samples possess large surface areas and superior acidities (up to 50 % higher) and outstanding stabilities compared to aluminosilicates prepared with state‐of‐the‐art methods. The obtained materials are evaluated in a series of acid‐catalyzed model reactions involving substrates of various chemical reactivity and size, enabling insight in the catalytic functionality of the introduced Brønsted and Lewis sites. The potential of the obtained materials is emphasized by the similar or superior acidity and catalytic performance compared to several benchmark industrial silica–alumina‐based catalysts.

show abstract

Synthesis of amorphous aluminosilicates by grafting: Tuning the building and final structure of the deposit by selecting the appropriate synthesis conditions

Cited by 35 publications

References 38 publications

Effect of acidity, hydrogenating phases and texture properties of catalysts on the evolution of asphaltenes structures during reside hydroconversion

Effect of acidity, hydrogenating phases and texture properties of catalysts on the evolution of asphaltenes structures during reside hydroconversion

Catalyst stabilization by stoichiometrically limited layer-by-layer overcoating in liquid media

Synthetic and Catalytic Potential of Amorphous Mesoporous Aluminosilicates Prepared by Postsynthetic Aluminations of Silica in Aqueous Media

Contact Info

Product

Resources

About