Templated self-assembly of ordered mesoporous silica on clay nanotubes

Abstract

Self-assembly of ordered silica arrays on clay nanotubes resulted in mesoporous MCM-41 type materials with enhanced catalytic properties.

Manganese and Cobalt Doped Hierarchical Mesoporous Halloysite-Based Catalysts for Selective Oxidation of p-Xylene to Terephthalic Acid

“…For the synthesis of Mn/Co oxidation catalyst based on MCM-41/HNT composite the following reagents were used: manganese (II) acetate tetrahydrate (CH 3 COO) 2 Mn × 4H 2 O (Aldrich, ≥99%; Steinheim, Germany), cobaltous (II) acetate tetrahydrate CH 3 COO) 2 Co × 4H 2 O (Aldrich, ≥98%; Steinheim, Germany) and MCM-41/HNT composite, earlier prepared according to literature procedure [24].…”

“…Halloysite clays were successfully applied as carriers for the tubular Ru nanocatalysts, revealing high activity in the hydrogenations of aromatic compounds and phenols [19][20][21][22][23]. Grafting of the ordered mesoporous materials, such as MCM-41 or SBA-15, onto halloysite template allows us to obtain new hierarchical systems with stronger mechanical properties and surface area up to 650 m 2 /g ( Figure 2) [21,24,25]. La-doped MCM-41/HNT composite revealed high efficacy as a sulfur-reducing additive for FCC (fluid catalytic cracking) catalyst, resulting in decrease of sulfur content by 25% and in the yield of gasoline fraction of about 45% [24,26,27].…”

“…Grafting of the ordered mesoporous materials, such as MCM-41 or SBA-15, onto halloysite template allows us to obtain new hierarchical systems with stronger mechanical properties and surface area up to 650 m 2 /g ( Figure 2) [21,24,25]. La-doped MCM-41/HNT composite revealed high efficacy as a sulfur-reducing additive for FCC (fluid catalytic cracking) catalyst, resulting in decrease of sulfur content by 25% and in the yield of gasoline fraction of about 45% [24,26,27]. Modified with CaO and MgO, MCM-41/HNT and SBA-15/HNT composites demonstrated high activity in the cracking of sulfones, formed after the oxidative desulfurization of diesel fraction, decreasing sulfur content from 450 up to 100 ppm [28].…”

Cellulose Nanofibrils and Tubular Halloysite as Enhanced Strength Gelation Agents

“…Halloysite nanotubes are widely employed as reinforcing agents in plastic composites [14,15,16,17], catalyst carriers [18,19], and biomedical tissue scaffolds [20,21,22]. The most exciting feature of the halloysite is its double-charged surface, which enables various strategies for the surface modification and loading of halloysite nanotubes for compatibility with hydrophilic or hydrophobic and positively and negatively charged matrices [23,24] and for the encapsulation of functional agents for corrosion protection [25,26], drug delivery [27,28], and other applications.…”

Multicomponent bionanocomposites based on clay-nanoarchitectures for electrochemical devices

“…Under this umbrella, diverse type of functional materials based on clay minerals have been also prepared, being pillared-clays and polymer-clay nanocomposites the best known examples on this topic [6]. Besides classical layered silicates, clays showing other morphologies as it is the case of fibrous (sepiolite and palygorskite) and tubular (halloysite and imogolite) clays, could be also interesting nanoparticulated solids for application of such concept [7][8][9][10]. In this, context, sepiolite and palygorskite are attracting growing interest for being used in the development of nanoarchitectured materials of interest in applications dealing topics from catalysis to biomedicine [7].…”