ELECTROCARBOXYLATION OF ORGANIC COMPOUNDS WITH CARBON DIOXIDE CATALYTZED BY METALLOPORPHYRINS(Ⅳ)——EFFECT OF VARIOUS FACTORS ON ELECTROCARBOXYLATION

The effects of various factors on the electrocarboxylation of organic compounds with carbon dioxide catalyzed by metalloporphyrin are studied.The optimal potential of electrocar- boxylation is -1.6 V(vs.SCE).A weak protic solvent methanol can enhance catalytic activity. Tetrabutylammonium iodide is the best one of five electrolytes.The yields and current efficiencies of electrocarboxylation are increased slowly as the concentration of catalyst increases.

ELECTROCARBOXYLATION OF ORGANIC COMPOUNDS WITH CARBON DIOXIDE CATALYZED BY METALLOPORPHYRINS(Ⅱ)——ELECTROSYNTHESIS OF SOME ORGANIC COMPOUNDS WITH CO_2 CATALYZED BY CoTPP

The catalyzation of CoTPP for electrocarboxylation of alkyl halides, alkenes and ketones with CO_2 are studied. The electrocarboxylation of these organic compounds with CO_2 in the presenec of catalyst can occur at more positive potential than that of no catalyst. The products of electrocarboxylation were identified by UV, IR and GC-MS. The electrocarboxylation mechanisms of different organic compounds are discussed.

Excellent electrocatalytic activity of benzil for direct reduction of CO2 as well as indirect reduction of pyridine:A kinetic view of the electrocarboxylation process

Benzil,1,2-diphenylethane-1,2-dione, was used as an excellent electrocatalyst for reduction of carbon dioxide, CO. The reduction overpotential of COwas reduced about 900 m V in the presence of a benzil mediator. The chemical reaction of the product of the electrocatalytic reduction of CO,(activated CO,CO) with pyridine at a glassy carbon electrode, GCE, surface and in an acetonitrile-ButNClOsolution was investigated by cyclic voltammetry, chronoamperometry and controlled potential coulometry.By chronoamperometry, the catalytic rate constant, k, for the electron transfer between benzil and COwas obtained as 8.1 ± 0.4 Ms. The results indicate that pyridine has a strong interaction with the activated CO. The coulometry method was used to obtain the product of the pyridine chemical reaction with CO. The spectral characterizations of FTIR,H andC NMR of the coulometry experiment product proved that the pyridine anion radical, Py, was carboxylated by CO, and isonicotinic acid is the final major product.

Toward green syntheses of carboxylates:Considerations of mechanisms and reactions at the electrodes for electrocarboxylation of organohalides and alkenes

Electrosynthesis and carbon dioxide(CO_(2))utilization both have gained interest in recent years due to the efforts to alleviate the climate crisis.Significant progress in the field of electrochemical carboxylation using CO_(2) or electrocarboxylation of organic substrates,particularly organohalides and alkenes,has been made in the past decade.Different components of electrocarboxylation experimental setup as well as the understandings of the mechanism play an important role in the success of the carboxylate syntheses.In this review,overview of the proposed mechanisms and the electrochemical setup are described.The significance of electrochemical components,such as the effect of different cathodes,sacrificial anode materials,and other additives,are explained.The examples of electrocarboxylation for both organohalides and olefins are provided.Lastly,the current trends in the field and future directions are discussed.

Electrocarboxylation of Anthrone to Anthracene-9-carboxylic Acid in the Presence of CO_2

Electrocarboxylation of anthrone in the presence of CO2 to anthrance-9-carboxylic acid directly was carried out. The electroreduction behavior of anthrone was examined by cyclic voltammetry in the absence and presence of CO2. Then the influences of the supporting electrolytes, temperature, electrode material and anthrone concentration on the carboxylation yield were investigated. Under the optimized conditions, anthrancene-9-carboxylic acid was obtained in a good yield（96.1%）.

ELECTROCARBOXYLATION OF ORGANIC COMPOUNDS WITH CARBON DIOXIDE CATALYZED BY METALLOPORPHYRINS(Ⅲ)——EFFECTS OF AXIAL LIGANDS ON CATALYTIC ACTIVITY OF CoTPP

The effects of peptides,amino acids and organic bases as an axial ligand on reaction ac- tivities in the electrocarboxylation of benzyl chloride with CO_2 catalyzed by CoTPP are reported. The imidazole organic base,peptide containing —SH and amino acid containing imidazolyl en- hance the catalytic activity.The effect of imidazole amounts on the catalytic activity of CoTPP is studied.

Advances in electrocarboxylation reactions with CO_(2)

Recently,significant research has been conducted on the conversion of carbon dioxide(CO_(2))into value-added chemicals.With the decreasing cost of clean electricity,electrochemical methods have emerged as potential approaches for converting and fixing CO_(2).Organic electrochemical synthesis is a promising method for utilizing CO_(2)because it transforms CO_(2)into higher-value chemicals.This review introduces the research aspects of CO_(2)conversion and the mechanisms of CO_(2)organic electrocarboxylation reactions.Recent progress in electrocarboxylation with CO_(2)is discussed,considering organic substrates and cathode types under different reaction mechanisms.Finally,the challenges and prospects in this field are highlighted with the aim of further promoting the fundamental understanding of CO_(2)organic electrocarboxylation.

Electrolytic Fixation of CO_2 by Electrocarboxylation of RX on Nanocrystalline TiO_2-Pt Cathode

Electrolytic fixation of CO2 was investigated by electrocarboxylation of organic halides (RX), and four esters (I, II, III, IV) were obtained in moderate yields. Electrochemical reduction esterifications of RX in the presence of CO2 were carried out on nanocrystalline TiO2-Pt electrode. The electrochemical behavior of RX in the presence of CO2 was investigated by the technique of cyclic voltammetry, and the probable reaction mechanism was proposed.

Efficient CO_(2) fixation with acetophenone on Ag-CeO_(2) electrocatalyst by a double activation strategy

The electrocarboxylation reaction is an attractive means to convert CO_(2) into valuable chemicals under ambient conditions,while it still suffers from low efficiency due to the high stability of CO_(2).In this work,we report a double activation strategy for simultaneously activating CO_(2) and acetophenone by silver-doped CeO_(2)(Ag-CeO_(2)) nanowires,featuring as an effective electrocatalyst for electrocarboxylation of acetophenone with CO_(2).Compared to the Ag foil,Ag nanoparticles and CeO_(2) nanowires,the Ag-CeO_(2)nanowire catalyst allowed to reduce the onset potential difference between CO_(2) and acetophenone activation,thus enabling efficient electrocarboxylation to form 2-phenyllactic acid.The Faradaic efficiency for producing 2-phenyllactic acid reached 91%at−1.8 V versus Ag/AgI.This double activation strategy of activating both CO_(2)and organic substrate molecules can benefit the catalyst design to improve activities and selectivities in upgrading CO_(2)fixation for higher-value electrocarboxylation.

SOLID-STATE ELECTROCHROMIC DISPLAY

A novel electrochromic display composed of polymeric solid electrolyte and ferroin electroactive species has been assembled, which presents a reversible variation of the color between light blue and red when a potential of 0.98 and 0.75 V is applied respectively. The results indicate that the response speed is increased by lowering the concentration of ferroin without decreasing color contrast.

Electrochemical Dicarboxylation of Styrene： Synthesis of 2-Phenylsuccinic Acid

Electrochemical dicarboxylation of styrene in the presence of atmospheric pressure of CO2 with a Ti cathode and a Mg rod anode readily took place efficiently in an acetonitrile solution containing 0.1 mol·L^-1 tetraethylammonium bromide to give 2-phenylsuccinic acid. Influences of the nature of the electrodes, the current density, the passed charge and the temperature on electrolysis were studied to optimize the electrolytic conditions, with the maximal isolated yield to be 86.07%. The mechanism of the elelctrocarboxylation process has been studied by cyclic voltammetry.