coordination of cu+ ions adsorbed on plausible sites of a silicalite-2 lattice has been investigated computationally via hybrid density functional theory method at the b3lyp/6-311+g* and b3lyp/def2-tzvp levels of theory using molecular models of the active site. the symmetrical coordination of cu+ ions to almost five oxygen atoms of the all-silica framework in six-membered ring (6mr) sites of t...

Reversible ionic liquids (RevILs) are that can be switched between molecular and forms via two stimuli, they assist in the synthesis of colloidal gold nanoparticles. The RevIL-stabilized nanoparticles deposited pores SBA-15 mesoporous silica incipient wetness without functionalization surface. location inside was confirmed by transmission electron microscopy technique a measured increase therma...

To discuss the potential role of the support for iridium catalyst, we have proceeded to prepare a series of supported catalysts with the same active phase content, but different silica content, to elucidate the changes in surface structure and the reaction process of hydrous hydrazine decomposition on catalyst. The obtained iridium catalysts contained 20 wt% of nanoparticles dispersed on spheri...

New modified acidic catalysts were prepared from the treatment of silica, titania and silica prepared from hydrolyzed tetraethyl orthosilicate (TEOS) with sulfuric and phosphoric acid. The sulfated and phosphated silica synthesized from TEOS were calcined at 450 and 650 ◦C. These catalysts were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmissio...

Nanoparticle (NP) sintering is a major cause of the deactivation supported catalysts. Raspberry-colloid-templated (RCT) catalysts are an emerging class materials that show unprecedented level sinter-resistance and exhibit high catalytic activity. Here comprehensive study origin NP stability accessibility in RCT using theoretical modeling, 3D electron microscopy, epitaxial overgrowth reported. T...

Palladium supported Al2O3 and SiO2 catalysts have been synthesized and evaluated for carbon monoxide oxidation in the presence of ozone. The factors affecting the CO oxidation such as Pd loading (wt%), contact time, reaction temperature and O3/CO molar ratio have been studied. The extent of ozone decomposition on Pd catalysts is proportional to the CO oxidation activity. High reaction temperatu...

The largest industrial application of olefin metathesis today is the synthesis of propylene from ethylene and butenes employing WO3 on SiO2, a relatively long-lived and regenerable catalyst that operates at 350–400 °C. It is widely proposed that high temperatures are required because the percentage of metal sites actually involved in the metathesis reaction is extremely low, or the reaction tha...

Examples of enantioselective catalysts, including homogeneous supported catalysts and biphasic liquid/liquid, are described and compared. In the case of asymmetric hydride transfer, polythiourea was proven to be more efficient for ruthenium-catalyzed reduction of aryl ketones, although the iridium complexes gave rise to higher ee when using amino sulfonamide bound to a polystyrene matrix. In th...