Search results for "CARBON DIOXIDE"
showing 10 items of 564 documents
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 (…
(Photo)electrocatalytic Versus Heterogeneous Photocatalytic Carbon Dioxide Reduction
2021
The present review summarizes some of the main results achieved in electrochemical, photocatalytic, and (photo)-electrocatalytic systems for the reduction of carbon dioxide. After a preliminary survey of the electrocatalytic and photocatalytic systems in terms of materials used, efficiencies, operating conditions, and product distribution, it is shown how the combination of the two approaches affords often higher efficiency than the single technologies and allows better control of the product distribution. In fact, the peculiar energetic distribution at the interface of irradiated semiconductors under opportune electrical bias enables enhancement of the spatial separation of the photogenera…
ELECTROCHEMICAL REDUCTION OF CARBON DIOXIDE TO FORMIC ACID AT TIN CATHODE IN DIVIDED AND UNDIVIDED CELLS: EFFECT OF OPERATING PARAMETERS
2015
The electrochemical reduction of carbon dioxide is considered a relevant topic for both the synthesis of chemicals and the decrease of global warming. Electrochemical processes could utilize excess energy from intermittent renewable sources to convert carbon dioxide in various products such as CO, formate and formic acid, methane and ethylene in water and oxalic acid, formic acid, CO as well as carboxylic acids (by reaction with suitable reagents such as aromatic ketones or benzylic halides) in aprotic solvents [1-3]. It has been shown that the selectivity of the process dramatically depends on the nature of the cathode. Four distinct classes of metal catalysts have been identified on the b…
REDUCTION OF CARBON DIOXIDE TO FORMIC ACID IN VARIOUS KINDS OF ELECTROCHEMICAL DEVICES.
2016
The reduction of carbon dioxide is considered a relevant topic for both the synthesis of chemicals and/or fuels and the decrease of global warming. Indeed, the utilization of CO2 as a feedstock for producing chemicals may contribute to alleviate global climate changes caused by the increasing CO2 emissions and provide new opportunities for catalytic and industrial development. In the last years, an increasing attention has been devoted to the electrochemical conversion of carbon dioxide to formic acid or formate in water. Thus, formic acid has a broad market and wide application range in dyeing, textile and leather industries, in rubber production, as an intermediate in the chemical and pha…
Duvalo (North Macedonia): A "volcano" without volcanic activity
2020
T he Duvalo locality is located in the SW of the Republic of North Macedonia, in the Ohrid region, near the village of Kosel. It is an area of strong soil degassing, called “volcano” by the local people despite volcanic activity has never been documented in the recent geologic history of the area [1]. A large area (thousands of sqm) shows signs of strong alteration and is devoid of vegetation. Until the 19thcentury sulphur was mined from this area [1]. In August 2019, a campaign of soil CO2 flux measurements and soil gas sampling was made. Duvalo is sometimes referred to as an active geothermal feature but no signs of enhanced geothermal gradient were found and the soil temperatures at 50 c…
CCDC 1827597: Experimental Crystal Structure Determination
2018
Related Article: Tomas Marqueño, David Santamaria-Perez, Javier Ruiz-Fuertes, Raquel Chuliá-Jordán, Jose L. Jordá, Fernando Rey, Chris McGuire, Abby Kavner, Simon MacLeod, Dominik Daisenberger, Catalin Popescu, Placida Rodriguez-Hernandez, Alfonso Muñoz|2018|Inorg.Chem.|57|6447|doi:10.1021/acs.inorgchem.8b00523
CCDC 1473652: Experimental Crystal Structure Determination
2017
Related Article: Mónica Giménez-Marqués, Néstor Calvo Galve, Miguel Palomino, Susana Valencia, Fernando Rey, Germán Sastre, Iñigo J. Vitórica-Yrezábal, Mónica Jiménez-Ruiz, J. Alberto Rodríguez-Velamazán, Miguel A. González, José L. Jordá, Eugenio Coronado, Guillermo Mínguez Espallargas|2017|Chemical Science|8|3109|doi:10.1039/C6SC05122G
Electrocarboxylation of Benzyl Halides through Redox Catalysis on the Preparative Scale
2006
The electrocarboxylation of benzyl halides to the corresponding carboxylic acids through homogeneous charge-transfer catalysis was investigated both theoretically and experimentally to determine the influence of the operative parameters on the yield of the process and on the catalyst consumption. Theoretical considerations, based on fast kinetics of redox catalysis, were confirmed by the electrocarboxylation of 1-phenyl-1-chloroethane catalyzed by 1,3-benzenedicarboxylic acid di methyl ester performed at a carbon cathode under different operative conditions. We obtained high yields of the target carboxylic acid and experienced a low catalyst consumption by operating with optimized [RX]bulk/…