Search results for "Electrosynthesi"

Direct Metal‐ and Reagent‐Free Sulfonylation of Phenols with Sodium Sulfinates by Electrosynthesis

2019

A novel electrochemical strategy for the synthesis of aryl sulfones by direct sulfonylation of phenols with sodium sulfinates has been developed. The C,S-coupling products are of particular interest for chemical synthesis, material sciences and pharmaceutical sciences. By using this metal- and reagent-free electrochemical method, aryl and diaryl sulfones can be obtained directly in good yields. The established one-step protocol is easy to perform, scalable, inherently safe, and enables a broad scope, which is not limited by quinoid-forming substrates.

Cover Feature: Direct Metal‐ and Reagent‐Free Sulfonylation of Phenols with Sodium Sulfinates by Electrosynthesis (Chem. Eur. J. 28/2019)

2019

Ni and Ni-Pd nanostructures electrodes for water-alkaline electrolyses

2017

Hydrogen production by water electrolysis (WE) is a very promising technology because it is a pollution free-process specially if renewable energy are employed. Up to day, the cost of hydrogen production by WE is higher than other available technologies, making WE not competitive. Many efforts have been made to improve WE performance, through the use of electrodes made of transition metal alloys (Pt2Mo, TiPt) as a cathode or pyrochlore type oxide (Tl2RuxIr2-xO7) as an anode [1]. In the field of water-alkaline electrolyzer, the development of cheap nanoporous nickel electrodes with high electrocatalytic features is one of the potential approaches to increase the WE performance [2]., A facile…

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.

Metal complexes of a novel heterocyclic benzimidazole ligand formed by rearrangement-cyclization of the corresponding Schiff base. Electrosynthesis, …

2018

The electrochemical oxidation of anodic metals (M = cobalt, nickel, copper, zinc and cadmium) in a solution of the ligand 1H-anthra[1,2-d]imidazol-6,11-dione-2-[2-hydroxyphenyl] [H2L] afforded homoleptic [ML] compounds. The addition to the electrochemical cell of coligands (L′) such as 2,2′-bipyridine (bpy) or 1,10-phenanthroline (phen) allowed the synthesis, in one step, of heteroleptic [MLL′] compounds. The crystal structures of H2L (1), [CoL(MeOH)]2 (2), [CoL(phen)]2 (3), [NiL(bpy)]2 (4), [CuL(bpy)] (5), [CuL(phen)] (6) and [CdL(bpy)]2 (7) have been determined by X-ray diffraction techniques. The crystal structures of 2, 3, 4 and 7 consist of dimeric species in which both metallic atoms …

Electrochemical oxidation of tetramethoxy precursor as a key step for the synthesis of coenzyme Q10

2007

The feasibility of electrosynthesis of coenzyme Q10 (1) by electrooxidation of tetramethoxy precursor (2) has been investigated at carbon, Pt and BDD anodes in a divided cell. The process strongly depends on the applied potential, anode material and water content of the solvent. At carbon anodes in CH3CN/CH2Cl2 + 0.15 M Bu4NBF4 at proper operative conditions high faradic efficiency (>60%) and excellent selectivity (95–97%) of the target product were obtained. Keywords: Electrosynthesis, Coenzyme Q10, Anodic oxidation

High-Temperature Electrolysis of Kraft Lignin for Selective Vanillin Formation

2020

Lignin represents the largest renewable resource of aromatic moieties on earth and harbors a huge potential as a sustainable feedstock for the synthesis of biobased aromatic fine chemicals. Due to the complex, heterogeneous, and robust chemical structure of the biopolymer, the valorization is associated with significant challenges. Unfortunately, technical lignins, which are a large side stream of the pulp and paper industries, are mainly thermally exploited. In this study, technical Kraft lignin was selectively electrochemically depolymerized to the aroma chemical vanillin. Using electricity, toxic and/or expensive oxidizers could be replaced. The electrodegradation of Kraft lignin was per…

Template electrosynthesis of La(OH)3 and Nd(OH)3 nanowires using porous anodic alumina membranes

2007

High quality arrays of Ln(OH)3 (Ln = La, Nd) nanowires have been successfully fabricated for the first time by an electrochemical process using anodic alumina membrane templates. A physico-chemical characterisation of electrodeposited hydroxides has been carried out by different techniques (XRD, SEM and EDX). The results show that the synthesized nanostructures are crystalline, dense, continuous, well aligned, and with high aspect ratio, suggesting further development of possible applications in the lanthanide family species. Keywords: Nanowires, Anodic alumina membranes, Hydroxide electrodeposition, Template, Lanthanide compounds

Facile crosslinking of poly(vinylpyrrolidone) by electro-oxidation with IrO2-based anode under potentiostatic conditions

2018

Abstract: The modification of polymer architectures by reaction with chemically adsorbed hydroxyl radicals has been thoroughly investigated by electrolyzing dilute aqueous solutions of the biocompatible polymer poly(vinylpyrrolidone) (PVP), using an undivided electrolytic cell with a Ti/IrO2–Ta2O5(DSA®) anode. Several electrolyses were performed to assess the influence of the applied potential, the circulated charge and the PVP concentration, which was always kept low to avoid chain overlapping. From the results obtained, it can be concluded that the electro-oxidation of PVP solutions using a cheap anode is an effective method to crosslink initially isolated polymer chains, eventually incre…

An electrochemical process to prepare and recycle biobased ionic liquids

2019

This manuscript describes the first electrosynthesis of biobased ionic liquids from L-valine, oxalic acid and glyoxal, which is energy-efficient, does not emit toxic waste and avoids the formation of inorganic waste. These ionic liquids were then used in the development of our electro-recycling process. While their recycling yields are still moderated due to recombination and disproportionation reactions, this unprecedented recycling technology is very promising in terms of environmental and economic gains. Indeed, it has a high energy efficiency, requires low cost equipment, allows a strong decrease of the price of such ionic solvents, limits the use of non-renewable resources and solves t…