Search results for "Electrochemical reduction"
showing 10 items of 21 documents
A Solar Photothermocatalytic approach for the CO2 conversion: Investigation of different synergisms on CoO-CuO/Brookite TiO2-CeO2 catalysts
2022
Abstract The photoactive features of the least common polymorph of TiO2, i.e. brookite, were combined with the thermocatalytic redox ones of cerium oxide, focusing on the effects of the addition of small amounts of Co-Cu oxides for the solar CO2 conversion. By considering the characterization data, a surface segregation of the hosted metal oxides on the TiO2-CeO2 composite was evidenced, and their presence increased the amount of oxygen vacancies and improved the charge carriers separation. The bimetallic oxides-based sample was the most performing one in the photocatalytic carbon dioxide reduction at room temperature. The formation of carbon monoxide and methane was 5 and 0.5 μmol g−1h−1, …
Origin and significance of the production of carbon dioxide during the ozonization of 13C-labeled D-glucose at different pH values.
2001
Abstract [1- 13 C], [2- 13 C] and [6- 13 C] d -glucose were, respectively, ozonized in a semi-batch reactor in acidic and basic conditions. The composition of the gas phase was evaluated by on-line mass spectrometry measurements. The quantitative and isotopic analyses of the carbon dioxide formed during ozonization are presented and discussed. The data, correlated with previous literature results, clearly show that at pH 2.5 the production of carbon dioxide from C-6 and C-1 carbon atoms is nearly equivalent. Conversely, at higher pH values, CO 2 is released with a greater selectivity from the reducing end. The importance of the decarboxylation reaction in the formation of by-products with f…
Pressurized CO2 Electrochemical Conversion to Formic Acid: From Theoretical Model to Experimental Results
2019
To curb the severely rising levels of carbon dioxide in the atmosphere, new approaches to capture and utilize this greenhouse gas are currently being investigated. In the last few years, many researches have focused on the electrochemical conversion of CO2 to added-value products in aqueous electrolyte solutions. In this backdrop, the pressurized electroreduction of CO2 can be assumed an up-and-coming alternative process for the production of valuable organic chemicals [1-3]. In this work, the process was studied in an undivided cell with tin cathode in order to produce formic acid and develop a theoretical model, predicting the effect of several operative parameters. The model is based on …
Polymer Synthesis in Supercritical Carbon Dioxide
2003
It is current opinion of most of the people involved in supercritical fluids (SCFs) technology that as the end of the twentieth century has been devoted to enlarge exploitation of compressed gases in separation processes the beginning of the twenty-first will be mainly aimed to improve their utilisation as solvents for reactions.
ELECTROCHEMICAL CONVERSION OF CARBON DIOXIDE TO FORMIC ACID IN A PRESSURIZZED FILTER PRESS CELL
2018
To limit the negative effect of carbon dioxide as a greenhouse gas, an interesting approach is the utilization of Carbon Capture and Conversion (CCC) methodology, which is focused on the use of CO2 waste as a feedstock to produce added-value product by using the excess electric energy from renewable source [1]. In this framework, an increasing attention has been devoted in the electrochemical conversion of carbon dioxide to formic acid in water [2,3], which is considered one of the more attractive pathway to convert CO2. Since the main hurdle of the CO2 reduction from aqueous solution is the low CO2 solubility in water, in this work, the effect of some operating parameters, including pressu…
Synthesis of dimethyl carbonate in supercritical carbon dioxide
2006
The reactivity of carbon dioxide with methanol to form dimethyl carbonate was studied in the presence of the n-butylmethoxytin compounds n-Bu3SnOCH3, n-Bu2Sn(OCH3)2 , and [n-Bu2(CH3O)Sn]2 O. The reaction occurred under solventless conditions at 423 K and was produced by an increase in CO2 pressure. This beneficial effect is primarily attributed to phase behavior. The mass transfer under liquid-vapor biphasic conditions was not limiting when the system reached the supercritical state for a CO2 pressure higher than 16 MPa. Under these conditions, CO2 acted as a reactant and a solvent.
Bio-based 1,3-diisobutyl imidazolium hydrogen oxalate [iBu 2 IM](HC 2 O 4 ) as CO 2 shuttle
2017
International audience; This manuscript describes the using of biosourced L-valine, oxalic acid and glyoxal to produce a biobased imidazolium hydrogen oxalate [iBu(2)IM](HC2O4) which is converted to its related hydrogen carbonate salt by a simple electrolysis without using strong base. The addition of weak protic acids to the latter compound leads to a rapid and quantitative CO2 release with formation of the starting hydrogen oxalate salt or a new halide free bio-based ionic liquid [iBu(2)IM](AcO) which is able to adsorb reversibly the CO2 at room temperature. The protonation reactions, combined with electrolysis, could then be a promising alternative solution for storage and transport of C…
Electrochemistry of Carbon Dioxide on Carbon Electrodes.
2016
Carbon electrodes have the advantages of being chemically inert at negative potential ranges in all media and high offset potentials for hydrogen evolution in comparison to metal electrodes, and therefore are the most suitable electrodes for electrochemistry and electrochemical conversion of CO2 into valuable chemicals. Herein we summarize on carbon electrodes the voltammetry, electrochemical and electrocatalytic CO2 reduction, as well as electron synthesis using CO2 and carbon electrodes. The electrocatalytic CO2 reduction using carbocatalyts and the future activities about electrochemical CO2 conversion are highlighted.
Leaded Bronze Alloy as a Catalyst for the Electroreduction of CO 2
2019
Reduction of oxygen to H2O2 at carbon felt cathode in undivided cells. Effect of the ratio between the anode and the cathode surfaces and of other op…
2019
Abstract In the last years, the electrochemical conversion of oxygen to hydrogen peroxide at carbon felt has been largely studied in order to define a new route for the production of H2O2 and to optimize the electro-Fenton process, which is based on the cathodic generation of H2O2. In particular, many studies regarding electro-Fenton process were carried out in undivided cells in order to avoid the costs of the separator and to reduce the cell potentials. Hence, in order to optimize the cathodic conversion of oxygen to H2O2 in undivided cells, the effect of many parameters linked to the anodic process were here evaluated. In particular, it was demonstrated that the performances of the proce…