In this thesis multi-component mass transport in thin supported amorphous silica membranes is discussed. These membranes are micro-porous, with pore diameters smaller than 4Å and show high fluxes for small molecules (such as hydrogen) combined with high selectivities for these molecules with respect to larger ones. The chemical and thermal stability of silica membranes are favourable compared t...

Palladium catalysts deposited over different types of silica (amorphous silica, mesoporousmolecular sieves, solids obtained by co-condensation of silicate precursors and many others) modified with suitable donor moieties have gained enormous importance due to their wide application as catalysts for cross-coupling and other synthetically useful organic reactions. This work provides an overview o...

Two triethoxysilyl-functionalized N-heterocyclic carbene ligands have been synthesized and used to prepare the corresponding second-generation ruthenium olefin metathesis catalysts. These complexes were then grafted onto silica gel, and the resulting materials were efficient heterogeneous catalysts for a number of metathesis reactions. The solid-supported catalysts were shown to be recyclable o...

UNLABELLED Silica-gold core-shell nanoparticles were used for plasmonic enhancement of rare earth fluorescence in sol-gel-derived TiO2:Sm3+ films. Local enhancement of Sm3+ fluorescence in the vicinity of separate gilded nanoparticles was revealed by a combination of dark field microscopy and fluorescence spectroscopy techniques. An intensity enhancement of Sm3+ fluorescence varies from 2.5 to ...

Titanium dioxide (TiO2) displays photocatalytic behavior under near-ultraviolet (UV) illumination. In another scientific field, it is well understood that the excitation of localized plasmon polaritons on the surface of silver (Ag) nanoparticles (NPs) causes a tremendous increase of the near-field amplitude at well-defined wavelengths in the near UV. The exact resonance wavelength depends on th...

A computational study of the cooperative effect of a small four-atom Co oxide cluster supported on the TiO2 anatase (100) surface in the electrochemical water splitting reaction is presented. The results have been obtained including explicit solvent water molecules by means of Car-Parrinello MD simulations. Reaction steps in the catalytic cycle determined involve the formation of TiO2 surface h...

We here demonstrated a novel square silica/titania mesoporous nanosheet which was prepared with hyperbranched poly(ether amine) nanosheets (hPEA-NSs) as a template. TEM and SEM images reveal that the obtained nanosheets possess a large aspect ratio with the average edge length of 1-2 μm and thickness of ~40 nm, respectively. Various metal nanoparticles such as gold, silver, and platinum can be ...

a highly efficient, simple and green solvent-free protocol for the preparation of poly-substituted quinolines via friedländer hetero-annulation reaction between 2-aminoaryl ketones and carbonyl compounds in the presence of silica-supported p2o5 (p2o5 / sio2) is described. in this method, the title compounds are obtained in high to excellent yields and in short reaction times.

silica supported phosphorus pentoxide (p2o5·sio2) is an efficient catalyst for synthesis of 1,3,5-substituted pyrazoles via the condensation of 1,3-diketones and hydrazines. simplicity of procedure, mild condition, being solvent-free, high yields, and easy workup are some advantages of this protocol.

The hydroboration of aldehydes and ketones using a silica-supported zirconium catalyst is reported. Reaction of Zr(NMe2)4 and mesoporous silica nanoparticles (MSN) provides the catalytic material Zr(NMe2)n@MSN. Exhaustive characterization of Zr(NMe2)n@MSN with solid-state (SS)NMR and infrared spectroscopy, as well as through reactivity studies, suggests its surface structure is primarily ≡SiOZr...