Search results for "E Conversion"
showing 10 items of 63 documents
L'amende honorable : rituel de conversion (16e-18e siècles)
2010
Imidazolium-Functionalized Carbon Nanohorns for the Conversion of CO2 Unprecedented Increase of Catalytic Activity after Recycling
2017
Carbon nanohorns (CNHs) were selected as a novel catalytic platform for the design of imidazolium based hybrid materials able to promote the conversion of carbon dioxide into cyclic carbonates. Several heterogeneous catalysts were prepared using a one-step procedure based on the radical polymerization of various bis-vinylimidazolium salts in the presence of pristine CNHs. The as-synthesized materials were tested for the fixation of CO2 into epoxides. The excellent catalytic performances were evaluated in terms of turnover number and productivity. The versatility of the above hybrids was proved using several epoxides as substrate. Catalysts recyclability was successfully verified for several…
Design of POSS-Imidazolium Supported Hybrids for the Conversion of Carbon Dioxide into Cyclic Carbonates
2018
Nowadays, the design of heterogeneous catalysts for the conversion of CO2 into useful chemical products is attracting the attention of the scientific community. The catalytic processes involving carbon dioxide as C1 feedstock are of growing interest for the sustainable development.1 The synthesis of cyclic carbonates by coupling CO2 with epoxides is one of the most interesting pathways for the conversion of carbon dioxide in terms of both atom economy and final products applications. Moreover, ionic liquids emerged as one of the most active catalysts for the production of cyclic carbonates starting from CO2 and epoxides.2 Herein, a series of heterogeneous catalytic systems bearing imidazoli…
Imidazolium Based Cross-Linked Nanostructures from POSS molecular bricks for the Efficient Conversion of Carbon Dioxide
2019
Polyhedral oligomeric silsesquioxanes (POSS) have been employed as molecular bricks for the synthesis of imidazolium cross-linked networks as heterogeneous catalyst for the conversion of carbon dioxide into cyclic carbonates via reaction with epoxides. Two hybrid materials with different nucleophilic species (bromide and iodide) have been prepared and characterized by means of elemental analysis, 13C and 29Si solid state NMR, thermogravimetric analysis and IR spectroscopy. The solids were tested as the sole catalyst under metal- and solvent-free reaction conditions showing full selectivity toward the formation of cyclic carbonates and outstanding productivity values. Several epoxides were r…
Materiali ibridi a base di POSS-Imidazolio per la conversione della CO2 in carbonati ciclici
2018
Lo sviluppo di catalizzatori per i processi di conversione della CO2 è una tematica che sta rivestendo un ruolo di rilevante importanza in ambito non soltanto accademico ma anche industriale grazie alla possibilità di trasformare un rifiuto, quale il diossido di carbonio, in una vasta gamma di prodotti. Nel presente lavoro, nuovi materiali ibridi costituiti da silsesquiossani poliedrici oligomerici (POSS) supportati su silice e funzionalizzati con sali di imidazolio sono stati progettati per la fissazione della CO2. 1 Tutti i solidi sono stati ampiamente caratterizzati e testati per la sintesi di carbonati ciclici tramite reazione tra CO2 ed epossidi in condizioni di reazione solvent-free (…
Conversion of Xylose to Furfural over Lignin-Based Activated Carbon-Supported Iron Catalysts
2020
In this study, conversion of xylose to furfural was studied using lignin-based activated carbon-supported iron catalysts. First, three activated carbon supports were prepared from hydrolysis lignin with different activation methods. The supports were modified with different metal precursors and metal concentrations into five iron catalysts. The prepared catalysts were studied in furfural production from xylose using different reaction temperatures and times. The best results were achieved with a 4 wt% iron-containing catalyst, 5Fe-ACs, which produced a 57% furfural yield, 92% xylose conversion and 65% reaction selectivity at 170 °
Bis(oxalato)chromium(III) complexes: Versatile tectons in designing heterometallic coordination compounds
2011
Abstract The mononuclear oxalato-containing chromium(III) complexes of general formula [Cr(AA)(C2O4)2]− (AA = α-diimine type ligand) are able to produce a large variety of heterometallic complexes by acting as ligands towards either fully solvated metal ions or preformed cationic complexes with available coordination sites. This review focuses on the structural diversity of the polynuclear complexes (oligonuclear and coordination polymers) which are generated by the bis(oxalato)chromate(III) species, with a special emphasis to their magnetic properties.
Ionic liquid binary mixtures: Promising reaction media for carbohydrate conversion into 5-hydroxymethylfurfural
2014
Abstract The conversion of carbohydrates into 5-hydroxymethylfurfural (5-HMF) has been studied in binary mixtures of ionic liquids (ILs), using strongly acidic resin Amberlyst 15 as the catalyst. In particular, both mono- and disaccharides, such as fructose, glucose and sucrose have been investigated. Considering the favorable effect exerted by chloride-based ionic liquids in the dissolution of carbohydrates, we used binary mixtures of 1-butyl-3-methylimidazolium chloride ([bmim][Cl]) with [bmim + ] based ionic liquids differing in size, shape and coordination ability of the anion ([bmim][BF 4 ], [bmim][N(CF 3 SO 2 ) 2 ], [bmim][N(CN) 2 ], [bmim][SbF 6 ] and [bmim][CF 3 SO 3 ]). Carbohydrat…
Jak pozostać sobą w obcym języku? Strategie konwersji językowej pisarzy pochodzenia słowiańskiego
2017
Ihe article is dcvoted to writers who after emigrating decided to change the language in which they wrote their books from their native language to the language of the country which became their second home. The strategies which are described in the article are determined by the personal experiences of the writers, for whom the choice of a second language in which their works were to be written became an opportunity to express various attitudes. Piotr Rawicz, a Jew of Polish origin, treated his literary debut - the novel Le sang du ciel, written in French - as an autobiography, which was expressed not in a direct manner but in a manncr based on intermediation of both the complex narrative d…
Osallistava sävellytysmenetelmä musiikinopetukseen : peruskoulun opetussuunnitelman 2014 tavoitteita ja oppimisen ydinmetaforia toteuttamassa
2017
In my case study, I used two composing tasks to examine how the inclusive composing method (OSM) I have developed promotes the achievement of the aims of the new core curriculum for basic education 2014 and realises the core metaphors of learning. I have created a learning triangle tool to determine how the musical contents, the principles for developing working culture and the goals of music teaching, transversal competences and national education are linked with the latter. In addition to participation and the gaining and creation of knowledge, I included operative competences in these core metaphors. I examined the means OSM offers to evaluate how the students achieve the aims of musical…