nan Sujandi

Amino-functionalized SBA-15 type mesoporous silica having nanostructured hexagonal platelet morphology

Amino-functionalized SBA-15 type mesoporous silicas having unique hexagonal platelet morphologies with short channels (100-300 nm) running parallel to the thickness of the nanostructured hexagonal platelet type morphologies have been directly synthesized by co-condensation of aminopropyltriethoxysilane (APTES) and sodium metasilicate as a silica source in the presence of Pluronic P123 triblock copolymer as a structure directing agent.

Styrene epoxidation over a SBA-15-supported Mn(III) Schiff-base complex

Abstract2,4-Di-tert-butyl-6-((E)-(propylimino)methyl)phenol as a Schiff-base ligand was immobilized onto an amino-functionalized SBA-15 through the reaction between di-tert-butyl-salicylaldahyde and the tethered amino group. The Mn(III) metal complex of the immobilized Schiff-base ligand was proven to be an active catalyst for the epoxidation of styrene withtert-butyl hydroperoxide as a terminal oxidant. The catalysts behaved as an oxidation catalyst in the epoxidation and could be used many times without structural degradation, leaching of active manganese species and significant activity loss. It has been concluded that the reversible redox cycles of the metal center play a key role during the epoxidation reaction, as well as in the reusability of the catalysts.

Short channeled amino functionalized SBA-15 catalysts for the liquid phase reaction between 2-hydroxyacetophenone and benzaldehyde

Abstract The short channeled amino-functionalized SBA-15 catalysts showed that remarkable enhanced catalytic activity for the liquid phase condensation of benzaldehyde and 2′-hydroxyacetophenone due to mesoporous channels running parallel to the short axis and thus facilitate for easy molecular transport of bulky products.

Microwave synthesis of SBA-15 mesoporous silica material for beneficial effect on the hydrothermal stability

Hydrothermally robust mesoporous SBA-15 silica material was synthesized for the first time using microwave with out adding any other chemical ingredients. For the sake of stability comparison, mesoporous SBA-15 material was also prepared by conventional hydrothermal technique. The stability of the material was tested by boiling water method and 29 Si-NMR Q 4 /Q 3 ratios. It was observed that SBA-15 synthesized under microwave conditions exhibited higher stability than that of hydrothermally synthesized SBA-15.

Heterogeneous catalysts containing basic and palladium centres for Heck reaction

Abstract Heterogeneous catalysts for Heck reaction were prepared by the reaction of Pd(OAc)2 with various nitrogen pendants supported on mesoporous molecular sieves. The catalysts have been tested in the reaction of butyl acrylate with bromobenzene to give butyl cinnamate. When the interaction of the aminogroups with palladium was too strong, the reaction proceeded rather slowly or not at all. Catalyst with N-{2-(N,N-diethyl-amino)ethyl}amine group reached 90 % of conversion after 30 minutes of reaction. Moreover, this catalyst was able to catalyse the reaction even without an external base i.e., to act as bifunctional catalyst.

Microwave assisted-direct synthesis of highly ordered large pore functionalized mesoporous SBA

Microwave sysnthesis has been successfully applied for the direct synthesis of organo-functionalized SBA-15 and 16 mesoporous materials through the co-condensations of organosilanes with sodium metasilicate in the presence of triblock copolymers as structure directing agents. The obtained materials have large pores, long range order of cubic and hexagonal mesostructures, and the loading of organo groups up to 10% of the silica frameworks.

Microwave synthesis of Fe-SBA-16 mesoporous silica and Friedel-Crafts type reaction

Iron-substituted SBA-16 materials have been synthesized by using direct microwave synthesis method under weak acidic conditions. Different iron species including isolated framework iron species, iron cluster and iron oxides were formed by adjusting the pH value and Si/Fe molar ratios. All the materials has been characterized by XRD, N 2 sorption and SEM. Lewis acid catalyzed Friedel-Crafts type alkylation reaction of benzene with benzylchloride has been investigated over Fe catalysts prepared with different pH values and iron contents.