1,721,028 research outputs found
One-pot conversion of citronellal into isopulegol epoxide on mesoporous titanium silicate
No full textCitronellal was converted into isopulegol epoxide in a one-pot two-step reaction achieving a 68% global yield on Ti-MCM-41 and designing a two-solvent catalytic system
PALLADIUM NANOPARTICLES SUPPORTED ON MESOPOROUS SILICA: APPLICATIONS IN CONTINUOUS-FLOW MIZOROKI-HECK REACTIONS
No full textHerein we wish to report our recent results in the Mizoroki–Heck alkenylations under batch and continuous-flow ligandless conditions, by using Metal Vapour Synthesis (MVS) derived Pd nanoparticles deposited on mesoporous silica powder (MCM-41)
Niobium(V) Saponite Clay for the Catalytic Oxidative Abatement of Chemical Warfare Agents
No full textIn-situ EXAFS investigation of non-acidic CVD-based Pt/KL catalyst under oxidation-reduction cycles
No full textThe role of surface reconstruction during the catalytic partial oxidtion of CH4: characterization and kinetic tests over 0.5 wt% Rh/α-Al2O3 systems
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Advanced Catalytic Technologies for Improved Global Security
No full textThe abatement of toxic chemical warfare agents (CWA) is conventionally achieved via stoichiometric reactions using strong oxidants with high environmental impact and/or via thermal degradation. The international Project “NanoContraChem”, in the framework of NATO Science for Peace and Security Programme, aims at obtaining innovative nanostructured inorganic materials for the catalytic decontamination of CWA. In the first year of activity, a class of heterogeneous catalysts has been designed to transform selectively and under mild conditions toxic organosulfur chemical agents in non-noxious products with reduced environmental impact. Nb(V)-containing saponite clay was identified as an optimal catalyst for the CWA oxidative abatement. The conventional synthetic protocol used to obtain saponite materials was modified to allow the insertion of Nb(V) ions within the inorganic framework of the clay, thus obtaining a bi-functional catalyst with strong oxidizing and acid properties. The cataly
On the role of carbonaceous material in the reduction of Cu2+ to Cu+ in Cu-ZSM-5 catalysts
No full textA multi-technique analytical approach has been used to show that carbonaceous material entrapped in the channels system of Cu- ZSM-5 catalysts may contribute to maintain the copper ions in the oxidation state +1. This suggests that the reduction of Cu2+ to Cu+ does not only occur via water elimination from CuOH+ species or via oxygen evolution from [Cu-O-Cu](2+) species, but also via oxidation of the carbonaceous materials to give CO and CO2. This mechanism occurs under high temperature (>300 degrees C) treatments in vacuo or He of Cu-ZSM-5 catalysts containing carbonaceous species and strongly adsorbed water molecules in the first coordination shell of the Cu2+. Our results may support the hypothesis about the roles of O-2 and hydrocarbons in the SCR of NOx; O-2 maintains together with hydrocarbons the optimal valence state of copper (Cu+) necessary to have the maximum conversion of NOx and hydrocarbons into N-2 and CO2. (C) 1999 Elsevier Science B.V. All rights reserved
Effect of Rh load on the surface properties and the catalytic performances of Rh/α-Al2O3 systems for CH4 partial oxidation
No full textPhotoelectrodes for Solar Energy Conversion and Water Remediation
No full textWO3,1 hematite (α-Fe2O3)2 and WO3-BiVO4 are wide band gap semiconductors that can be obtained under nanocrystalline form and serve as the photo-anodic compartment (i.e. the oxygen evolving compartment) of a photoelectrochemical cell for solar fuel production. In this contribution some results about the charge transfer dynamics at the semiconductor/electrolyte interface gained by combining Transient Absorption Spectroscopy and Electrochemical Impedance Spectroscopy are reported. Viable approaches to improve the photoelectrochemical response of these materials are also discussed. Finally, we focus on the environmental applications of these materials, by considering the degradation of some Contaminants of Emerging Concern which are present in potable water and are impervious to conventional decontamination techniques.
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