Reactivity and applications of layered silicates and layered double hydroxides

Abstract

Layered materials, such as layered sodium silicates and layered double hydroxides (LDHs), are well-known for their remarkable adsorption, intercalation and swelling properties. Their tunable interlayers offer an interesting avenue for the fabrication of pillared nanoporous materials, organic-inorganic hybrid materials and catalysts or catalyst supports. This perspective article provides a summary of the reactivity and applications of layered materials including aluminium-free layered sodium silicates (kanemite, ilerite (RUB-18 or octosilicate) and magadiite) and layered double hydroxides (LDHs). Recent developments in the use of layered sodium silicates as precursors for the preparation of various porous, functional and catalytic materials including zeolites, mesoporous materials, pillared layered silicates, organic-inorganic nanocomposites and synthesis of highly dispersed nanoparticles supported on silica are reviewed in detail. Along this perspective, we have attempted to illustrate the reactivity and transformational potential of LDHs in order to deduce the main differences and similarities between these two types of layered materials.

Glycerol dehydration catalyzed by MWW zeolites and the changes in the catalyst deactivation caused by porosity modification

“…The main distinct aspect between conventional and layered zeolites comes from the fact that adsorption and catalysis in lamellar zeolites occur almost expressly at the surface and not inside pores [15]. Moreover comparing 2D zeolites and layered material in general, zeolites exhibit an advantage in porosity since there are pores in own layers [16].…”

Zinc influence on the formation and properties of Pt/Mg(Zn)AlO catalysts synthesized from layered hydroxides

“…The synthesis of the layered hydroxides having different composition and carbonate counter ions was described in detail in [1][2][3][4][5][13][14][15]40]. The synthesis procedure included coprecipitation of Mg 2+ , Zn 2+ and Al 3+ hydroxides from aqueous solutions (1 mol/L) of nitrate salts upon their interaction with the solutions containing carbonate and hydroxide ions (1 mol/L).…”

“…Layered double hydroxides (LDH) with the general formula [M (II) 1Àx M(III) x (OH) 2 ][A nÀ ] x/n mH 2 O, where M is a metal and A is an anion, are widely employed in various fields [1][2][3][4][5][6]. The catalytic application of these materials is related to the synthesis of multicomponent catalysts for aldol condensation, alkylation, polymerization, hydrogenation, steam reforming and other reactions [7][8][9][10].…”

Application of Organo-Magadiites for the Removal of Eosin Dye from Aqueous Solutions: Thermal Treatment and Regeneration

“…Layered materials have attracted great attention due to their wide application in different fields and to their characteristic cation exchange capacity, acceptance of intercalated guest molecules, exfoliation in different polymer matrixes, and catalytic 3 properties [1]. The layered silicate, magadiite, is an important member of this family, and it is easily prepared in the laboratory by the hydrothermal treatment of a silica source dissolved in an alkaline solution at a specific temperature of 150 °C for a period of time varying from two to three days [2].…”