Search results for "catalyst"

TiO2/Ag2O immobilized on cellulose paper: A new floating system for enhanced photocatalytic and antibacterial activities

2021

Paper-TiO2-Ag2O floating photocatalysts were produced under mild condition and their photocatalytic activity for the degradation of aromatic amine under sunlight stimulant was investigated. Characterizations by Raman, XRD, XPS, DRS and PL confirmed the presence of TiO2 and Ag2O, and the morphology of the appended TiO2/Ag2O layer was probed by FE-SEM. The photocatalytic activity of the prepared samples was investigated by the degradation of aniline (AN) in water under simulated sun-light illumination and constrained conditions, i.e. non-stirring and non-oxygenation. The presence of Ag2O combined with TiO2 was shown to improve the resistance of paper to bacteria attack, thus increasing the du…

Structural characterization of Pd-Ag and Pd-Cu bimetallic catalysts by means of EXAFS, WAXS and XPS

2000

Bimetallic Pd-Ag and Pd-Cu pumice-supported catalysts have been synthesized following different preparation procedures with the aim of improving the selectivity and reactivity of monometallic Pd/pumice systems. The structural characterization, carried out by X-ray Diffraction, X-ray Absorption and X-ray Photoelectron Spectroscopy, allowed to investigate the importance of the preparation procedures in the alloy formation.

Codeposition of Fe 3 O 4 nanoparticles sandwiched between g-C3N4 and TiO2 nanosheets: Structure, characterization and high photocatalytic activity fo…

2019

Novel ternary nanocomposite photocatalysts based on g-C3N4 /Fe3O4 /TiO2 nanosheet were synthesized using simple solid combustion, hydrothermal and wetness impregnation methods. The g-C3N4 nanosheet (2D)/ Fe3O4 /TiO2 nanosheet (2D) triad-interface nanocomposite arranged in the form of Fe 3 O 4 nanoparticle was sandwiched and effectively dispersed on the surface between g-C3N4 and TiO2 nanosheets. The synthesized composites were characterized by some specific techniques such as X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electronic microscopy (FE-SEM), transmission electron microscope (TEM), vibrating sample magnetometer (VSM), specific su…

Activity and Thermal Stability of Cobalt(II)-Based Olefin Polymerization Catalysts Adorned with Sterically Hindered Dibenzocycloheptyl Groups.

2019

Five examples of unsymmetrical 2-(2,4-bis(dibenzocycloheptyl)-6-methylphenyl- imino)ethyl)-6-(1-(arylyimino)ethyl)pyridine derivatives (aryl = 2,6-Me2C6H3 in L1

Constant potential rate theory – general formulation and electrocatalysis

2021

Confined Pt-1(1+) Water Clusters in a MOF Catalyze the Low-Temperature Water-Gas Shift Reaction with both CO2 Oxygen Atoms Coming from Water

2018

[EN] The synthesis and reactivity of single metal atoms in a low-valence state bound to just water, rather than to organic ligands or surfaces, is a major experimental challenge. Herein, we show a gram-scale wet synthesis of Pt-1(1+) stabilized in a confined space by a crystallographically well-defined first water sphere, and with a second coordination sphere linked to a metal-organic framework (MOF) through electrostatic and H-bonding interactions. The role of the water cluster is not only isolating and stabilizing the Pt atoms, but also regulating the charge of the metal and the adsorption of reactants. This is shown for the low-temperature water-gas shift reaction (WGSR: CO + H2O CO2 + H…

C3N4/reduced graphene oxide photocatalysts loaded with Ag or Ag/Pt for H2 evolution from aqueous solution of triethanolamine

2023

Composites of C3N4/reduced graphene oxide have been used as photocatalysts for triethanolamine photo- reforming with H2 generation in aqueous solution. The rate of H2 production over the Ag loaded best per- forming photocatalyst reached 525 μmol⋅h

Highly robust and selective system for water pollutants removal: How to transform a traditional photocatalyst into a highly robust and selective syst…

2019

Highly porous monolithic aerogels based on ZnO photocatalyst and syndiotactic polystyrene (s-PS) were obtained by supercritical CO2 treatment of ZnO/s-PS gels. The prepared aerogels were characterized and their photocatalytic activity was evaluated using phenol and toluene as water pollutant models. The s-PS nanoporous crystalline phase, able to absorb pollutant molecules, was proven to be necessary to ensure high photocatalytic efficiency as the aerogel acts not only as a support, but also as pollutant pre-concentrator. The reusability of ZnO/s-PS aerogels is also strong showing no decrease in photocatalytic activity after six consecutive degradation trials. Finally, the aerogel matrix pre…

High crystallinity polyethylene obtained in biphasic polymerization using pyridinium chloroaluminate ionic liquid

2014

A series of N-n-alkylpyridinium chloroaluminate ionic liquids [C n -py][AlCl4] (where n-alkyl = n-butyl, n-hexyl, and n-octyl) was applied as a medium of the Cp2TiCl2 catalyst, activated by AlEtCl2 or AlEt2Cl, to evaluate the influence of the studied ionic liquids on the performance of the biphasic ionic liquid/hexane ethylene polymerization and the properties of the produced polyethylene (PE). The best results were obtained using N-n-butylpyridinium chloroaluminate. The polyethylene obtained in the biphasic polymerization have the high crystallinity, which was confirmed by DSC, WAXS and PALS methods, as well as the bulk density comparable to commercial HDPE. These unique properties results…

Multi-Alkenylsilsesquioxanes as Comonomers and Active Species Modifiers of Metallocene Catalyst in Copolymerization with Ethylene.

2018

The copolymers of ethylene (E) with open-caged iso-butyl-substituted tri-alkenyl-silsesquioxanes (POSS-6-3 and POSS-10-3) and phenyl-substituted tetra-alkenyl-silsesquioxane (POSS-10-4) were synthesized by copolymerization over the ansa-metallocene catalyst. The influence of the kind of silsesquioxane and of the copolymerization conditions on the reaction performance and on the properties of the copolymers was studied. In the case of copolymerization of E/POSS-6-3, the positive comonomer effect was observed, which was associated with the influence of POSS-6-3 on transformation of the bimetallic ion pair to the active catalytic species. Functionality of silsesquioxanes and polymerization par…