TiO2 nanoparticles were synthesized by hydrothermal method at 180 ̊C from TiOSO4 aqueous solution with1m/l concentration. The obtained products were coated with silica by means of a seeded polymerization technique for a coating time of 1440 minutes to obtain well defined TiO2@SiO2 core-shell structure. The uncoated and coated nanoparticles were characterized by using X-Ray diffraction technique ...

The impact of immobilization of oxazaborolidines supported on silica via different substituents on the boron and nitrogen atoms is evaluated in the enantioselective reduction of acetophenone. The performances of the homogeneous analog oxazaborolidines and silica supported-ones are compared by varying different parameters. This article deals with the synthesis, characterization and catalytic eva...

Titanium-substituted silicalites, prepared from two different silicalite precursors, are characterized using Raman spectroscopy, X-ray absorption spectroscopy, pyridine adsorption, and methanol oxidation. The silicalite precursors used are tetraethyl orthosilicate and Ludox AS 40. Two different types of titania species are observed in the titania silicalites. Below 1.6 mole% Ti/(Ti + Si), a dis...

The specific role played by small gold nanoparticles supported on the rutile TiO2( 110) surface in the processes of adsorption and dissociation of H2 is discussed. It is demonstrated that the molecular and dissociative adsorption of H2 on Au(n) clusters containing n = 1, 2, 8 and 20 atoms depends on cluster size, geometry structure, cluster flexibility and the interaction with the support mater...

The catalytic oxidation of sulfur dioxide to sulfur trioxide over several binary (MxOy/TiO2) and ternary (V2O5/MXOY/TiO2) supported metal oxide catalysts was systematically investigated. The supported metal oxide components were essentially 100% dispersed as surface metal oxide species, as confirmed by Raman spectroscopy characterization. The sulfur dioxide oxidation turnover frequencies of the...

It is demonstrated that the support effects play a crucial role in the gold nanocatalysis. Two types of support are considered—the “inert” support of hexagonal boron nitride (h-BN) with the N and B vacancy defects and the “active” support of rutile TiO2(110). It is demonstrated that Au and Au2 can be trapped effectively by the vacancy defects in h-BN. In that case, the strong adsorption on the ...

It has been found that the electrocatalytic properties of metallic nanoparticles supported on transition metal oxides are affected by existing strong metal–support interaction (SMSI). Herein, effects SMSI electrocatalysis hydrogen evolution reaction (HER) were investigated in acid electrolyte using Pt and Ag carbon titanium oxide (TiO2). High-resolution transmission electron microscopy (HR–TEM)...

Silica sodium carbonate (SSC) has been used as a valuable silica-supported catalyst for the preparation of a range of known and novel pyrano coumarins via the three-component reactions of aryl aldehydes, active methylene compound (malononitrile or ethyl cyanoacetate), and hydroxycoumarin (5,7-dihydroxy-4-substituted coumarins or 4-hydroxycoumarin). The heterogeneous catalyst showed much the sam...

Diarylamines are an important class of widely utilized chemicals, and development of diverse procedures for their synthesis is of great importance. Herein, we have successfully developed novel versatile catalytic procedures for the synthesis of diarylamines through acceptorless dehydrogenative aromatization. In the presence of a gold-palladium alloy nanoparticle catalyst (Au-Pd/TiO2), various s...