Electrolysis Of Acid Research Articles

Fluoroaliphatic esters of fluorosulfonic acid. 1. Reactions of higher fluoroolefins with electrochemically generated peroxydisulfuryl difluoride

The electrolysis of fluorosulfonic acid in the presence of perfluoro-2-alkenes in an electrolyzer without a diaphragm results in the formation of a mixture of products, whose composition is determined by both the anodic and cathodic processes.

Ceramic diaphragms for electrolysis of mineral acids

The diaphragm is one of the most important components of the electrolyzer, having a considerable influence on the energy factors of the electrolysis process. In the production of electrolysis products in solution, the diaphragm should exert a high resistance to the diffusion of the electrolyte and have a low resistance tothe passage of the electric current, which causes special demands to be placed on the nature of the porous diaphragm. In this case, it is particularly important that the diaphragm be chemically resistant to the action of those agents which are formed on the electrodes, and these are: acids, alkalis, or strong oxidizers.

Gas-phase electrolysis of hydrobromic acid using PTFE-bonded carbon electrode

The gas phase electrolysis of hydrobromic acid (48 wt%) was investigated for the development of the bromine-based thermochemical hydrogen production process, by using PTFE-bonded carbon electrode. Investigation of the anodic behaviour by using a half cell showed that the electrode performance was largely affected by the type of carbon used, the fabrication pressure, the content of PTFE, and the hydrophobicity of the electrode. The anodic potential was stable for 10 h at the current density of 144 mA cm −2. The loading of Pt catalyst was very effective on the cathodic behavior. When adopted to a fuel-cell type electrolyser, the PTFE-bonded electrode showed better performance than the graphite-felt electrode; the current density of 120 mA cm −2 and HBr conversion of 45% were achieved at cell voltage of 0.80 V at 423 K.

An ultrastructural analysis of afferent terminals to the anterior pretectal nucleus in the cat.

The synaptic organization of three kinds of afferent projections in the feline anterior pretectal nucleus (PTA) was analyzed by a combination of the degeneration and retrograde transport of horseradish peroxidase (HRP) techniques, along with that of the degeneration and anterograde transport of HRP techniques. Retrograde labeling of PTA neurons was performed by injections of HRP in the dorsal accessory olivary nucleus (DAO). Three kinds of afferent sources of the PTA--the cerebral motor cortex, the anterior interpositus nucleus of the cerebellum, and the gracile nucleus--were subjected to electrolysis, suction, or injection of kainic acid or HRP for identification of axon terminals of each system. Axon terminals of these different afferent sources identified by degeneration or anterograde HRP transport techniques showed similar morphological features: They were relatively large (1-6.5 microns in diameter), contained round or ovoid synaptic vesicles, and made asymmetrical synaptic contacts. When the degeneration study was combined with the retrograde HRP transport technique, some degenerating terminals from the motor cortex, anterior interpositus, or gracile nuclei were found to synapse directly with HRP-labeled dendrites or somata of the PTA neurons projecting to the DAO. Each combination of the degeneration and anterograde HRP transport techniques revealed the fact that neither degenerating nor HRP-labeled terminals were found to synapse with the same neuronal structure. These observations indicate that the PTA neurons relay afferent inputs from three different sources directly to the DAO, and that there is a possibility of parallel processing rather than convergence of three different afferent systems via the PTA to the DAO.

ChemInform Abstract: Carbon‐Carbon Bond Fragmentation Through Oxidative Electrolysis of Carboxylic Acids and Its Application to the Synthesis of Malyngolide.

AbstractStarting with 3‐methoxybenzoic acid (I), a synthesis of malyngolide (VIIa) together with its epimer (VIIb) is presented.

Electrochemical polymerization of dicarboxylic acids—IV. Polymerization of sebacic acid

The electrolysis of sebacic acid was investigated in methanol, methanol:pyridine (1:1) and methanol:acetonitrile (1:1). The various products were analyzed. In methanol, the major product was the oligomeric carboxylic acid fraction (55%) and the yield of oligomeric hydrocarbons and polymer was lower. With the other two solvents, the polymer was the major product. Four types of hydrocarbons were formed: n-alkane, 1-alkene, x-alkene (the position of the double bond is not known) and cycloalkane. The polymers obtained in all the solvents had the character of cross-linked and branched polyethylene, having ester and methoxy groups. These polymers did not suffer degradation during basic hydrolysis. In comparison with adipic acid, sebacic acid had more tendency to yield polymer and carboxylic acids than hydrocarbons.

Electrochemical polymerization of dicarboxylic acids—III. Quantitative results in the electrolysis of adipic acid

The electrochemical polymerization of adipic acid via the Kolbe synthesis was investigated in methanol, methanol-pyridine and methanol-acetonitrile mixtures. The complex variety of products formed from C 4 and higher hydrocarbons, methyl esters, methyl ethers, lactones, oligomers and polymers in the various solvents were analyzed and compared. Generally the major products were the hydrocarbons and the polymers; the yield of the former decreased with increasing pyridine concentration and that of the latter increased.

Carbon-carbon bond fragmentation through oxidative electrolysis of carboxylic acids and its application to the synthesis of malyngolide

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCarbon-carbon bond fragmentation through oxidative electrolysis of carboxylic acids and its application to the synthesis of malyngolidePeter G. M. Wuts and Minn Chang ChengCite this: J. Org. Chem. 1986, 51, 14, 2844–2847Publication Date (Print):July 1, 1986Publication History Published online1 May 2002Published inissue 1 July 1986https://doi.org/10.1021/jo00364a053RIGHTS & PERMISSIONSArticle Views199Altmetric-Citations8LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (603 KB) Get e-Alerts Get e-Alerts

Chirale Synthesebausteine durch Kolbe‐Elektrolyse enantiomerenreiner β‐Hydroxy‐carbonsäurederivate. (R)‐ und (S)‐Methyl‐sowie (R)‐Trifluormethyl‐γ‐butyrolactone und ‐δ‐valerolactone

Chiral Building Blocks for Syntheses by Kolbe Electrolysis of Enantiomerically Pure β‐Hydroxybutyric‐Acid Derivatives. (R)‐ and (S)‐Methyl‐, and (R)‐Trifluoromethyl‐γ‐butyrolactones, and ‐δ‐valerolactonesThe coupling of chiral, non‐racemic R* groups by Kolbe electrolysis of carboxylic acids R*COOH is used to prepare compounds with a 1.4‐ and 1.5‐distance of the functional groups. The suitably protected β‐hydroxycarboxylic acids (R)‐ or (S)‐3‐hydroxybutyric acid, (R)‐4,4,4‐trifluoro‐3‐hydroxybutyric acid (as acetates; see 1–6), and (S)‐malic acid (as (2S,5S)‐2‐(tert‐butyl)‐5‐oxo‐1,3‐dioxolan‐4‐acetic acid; see 7) are decarboxylatively dimerized or ‘codimerized’ with 2‐methylpropanoic acid, with 4‐(formylamino)butyric acid, and with monomethyl malonate and succinate. The products formed are derivatives of (R,R)‐1,1,1,6,6,6‐hexafluoro‐2,5‐hexanediol (see 8), of (R)‐5,5,5‐trifluoro‐4‐hydroxypentanoic acid (see 9,10), of (R)‐ and (S)‐5‐hydroxyhexanoic acid (see 11) and its trifluoro analogue (see 12, 13), of (S)‐2‐hydroxy‐ and (S,S)‐2,5‐dihydroxyadipic acid (see 23, 20), of (S)‐2‐hydroxy‐4‐methylpentanoic acid (‘OH‐leucine’, see 21), and of (S)‐2‐hydroxy‐6‐aminohexanoic acid (‘OH‐lysine’, see 22). Some of these products are further converted to CH3‐ or CF3‐substituted γ‐ and δ‐lactones of (R)‐ or (S)‐configuration (14, 16–19), or to an enantiomerically pure derivative of (R)‐1‐hydroxy‐2‐oxocyclopentane‐1‐carboxylic acid (see 24). Possible uses of these new chiral building blocks for the synthesis of natural products and their CF3 analogues (brefeldin, sulcatol, zearalenone) are discussed. The olfactory properties of (R)‐ and (S)‐δ‐caprolactone (18) are compared with those of (R)‐6,6,6‐trifluoro‐δ‐caprolactone (19).

ChemInform Abstract: ELECTRODE MATERIALS FOR HYDROBROMIC ACID ELECTROLYSIS IN TEXAS INSTRUMENTS′ SOLAR CHEMICAL CONVERTER

AbstractFür den von Texas lnstruments entwickelten SCC (solar chemical converter), der Sonnenenergie über die HBr‐Elektrolyse in chemische Energie umwandelt, ergaben sich als bestes Kathodenmaterial zerstäubte dünne Pt/Ir‐Filme und zerstäubte Ir/Iridiumoxid‐Filme als Anodenmaterial.

Performance Predictions for Solar‐Chemical Convertors by Computer Simulation

A computer model which simulates the operation of Texas Instruments solar‐chemical convertor (SCC) was developed. The model allows optimization of SCC processes, material, and configuration by facilitating decisions on trade‐offs among ease of manufacturing, power conversion efficiency, and cost effectiveness. The model includes various algorithms which define the electrical, electrochemical, and resistance parameters and which describe the operation of the discrete components of the SCC. Results of the model which depict the effect of material and geometric changes on various parameters are presented. The computer‐calculated operation is compared with experimentally observed hydrobromic acid electrolysis rates.

Performance Predictions for Solar‐Chemical Converters Based on Photoelectrochemical I‐V Curves

Texas Instruments' solar energy system contains a solar‐chemical converter (SCC) which converts solar energy into chemical energy via the electrolysis of hydrobromic acid into hydrogen and bromine . Previous predictions of SCC performance have employed electrical dry‐probe data and a computer simulation model to predict the generation rates. The method of prediction described here makes use of the photoelectrochemical I‐V curves to determine the “wet”‐probe parameters of , , FF, and efficiency for anodes and cathodes. The advantages of this technique over the dry‐probe/computer simulation method are discussed. A comparison of predicted and measured generation rates is presented. Solar to chemical efficiencies of 8.6% have been both predicted and measured for the electrolysis of 48% to hydrogen and bromine by a full anode/cathode array. Individual cathode solar to hydrogen efficiencies of 9.5% have been obtained.

Electrode Materials for Hydrobromic Acid Electrolysis in Texas Instruments' Solar Chemical Converter

Texas Instruments has developed a solar chemical converter (SCC) which converts solar energy into chemical energy via the electrolysis of hydrobromic acid. Various materials were evaluated as anodes and cathodes for the electrolysis of the acid. Emphasis was placed on obtaining low overvoltage electrodes with good long‐term stability. Sputtered platinum‐iridium thin films were identified as the best choice as the cathode material, and sputtered iridium and iridium oxide thin films were identified as the best choice as anode materials. Electrochemical measurements indicate that low overvoltage losses are encountered on these materials at operating current densities in the SCC. Accelerated corrosion tests of the materials predict acceptable electrode stability for 20 years in an environment representative of on‐the‐roof service.

Electrolysis of Strong Acids and Strong Alkalis with Special Reference to Their Non-Faradaic Behaviour

Electrolysis of Strong Acids and Strong Alkalis with Special Reference to Their Non-Faradaic Behaviour

Reactions of fluoroalkyl radicals generated electrochemically. Part 2. Addition of heptafluoropropyl radicals to methyl methacrylate

Heptafluoropropyl radicals, generated by the electrolysis of heptafluorobutyric acid, reacted with methyl methacrylate to give a mixture of products of the type RFCH2CH(Me)X, RFCH2C(Me)(RF)X, [RFCH2C(Me)X]2 and RFCHC(Me)X, where RF= C3F7 and X = CO2Me. Also formed by electrochemical oxidation of the product of the intial radical addition reaction were CH2C(CH2RF)X, (RFCH2)2CHX, and (RFCH2)2C(RF)X, this being the preferred process. A trimeric and second dimeric product were also formed.

Electrosyntheses based on reactions of addition of electrochemically generated radicals to ethylene and its derivatives—I. Electrosynthesis products and the influence of electrolysis conditions on the addition product yield

It is shown that radicals electrochemically generated under Kolbe and Brown—Walker syntheses can, in principle, be added to ethylene and is derivatives. Products formed under electrolysis of acetic, monochloroacetic, trichloroacetic, trifluoroacetic, propionic, oxalic and other acids, as well as monomethylglutarate and monomethyladipinate, in the presence of various acceptors, such as ethylene, propylene, fluoroolefins and dimethyl ester of maleic acid, are separated and identified. It is shown that products of type ▪ The influence of electrolysis conditions on the addition product yield is investigated. An increase in the acceptor concentration is shown to increase the total yield of addition products and the yield of higher oligomers. An increase in the current density reduces the yield of addition products.

Efficient Solar to Chemical Conversion: 12% Efficient Photoassisted Electrolysis in the [p-type InP(Ru)]/HCl-KCl/Pt(Rh) Cell

The photoelectrochemical cell [$p$-type InP(Ru)]/HCl-KCl/Pt(Rh) converts 12% of the incident solar energy into two useful chemicals, hydrogen and chlorine, by photoassisted electrolysis of aqueous hydrochloric acid. At the threshold for electrolysis, the voltage required is reduced from 1.3 to 0.65 V. Hydrogen evolution takes place at microscopic islands of catalysts such as Rh, Ru, and Pt. The high efficiency of the cell derives from a thin surface oxide on InP, preventing carrier recombination, and from efficient transport of electrons to the catalyst.

Electrolysis of hydrobromic acid

The electrolysis of hydrobromic acid is of interest for hybrid cycles. It is shown that the electrolysis is feasible on a laboratory scale with bipolar graphite electrodes. Graphite is actually the only practical material. The high hydrogen overvoltage of graphite can be reduced to a large extent by adding small amounts of Pd or Pt salts directly to the electrolyte. The bromine overvoltage is much lower than that for chlorine and can be neglected. The working temperature may be higher than for present day H 2O or HCl electrolysis. Under conventional conditions several kA/m 2 can be obtained below 1 V.

Electrochemical fluorination of carboxylic acids in presence of fluoride anion

1. The electrolysis of carboxylic acids at a Ni anode in the presence of F− anion results in their decarboxylation and the subsequent exhaustive fluorination of the adsorbed alkyl radical. 2. The electrochemical oxidation of the adsorbed alkyl radicals with a branched carbon chain is accompanied by less destruction when compared with straight-chain radicals. 3. The adsorbed alkyl radicals are partially isomerized during fluorination; straightchain perfluorocarbons are formed from branch radicals to a greater degree than the reverse transformation of straight-chain alkyl radicals to isoperfluorocarbons.

Reactions of fluoroalkyl radicals generated electrochemically. Part 1. Additions of trifluoromethyl radicals to olefinic and acetylenic bonds

Trifluoromethyl radicals, generated by the electrolysis of trifluoroacetic acid in acetonitrile–water–sodium hydroxide reacted with olefins CH2CHX (X = C3H7, C4H9, C5H11, CO2CH3, CN, and CH2CO2CH3) to give a mixture of products of the type CF3CH2CH2X, CF3CHCHX, CF3CH2CH(CF3)X, and (CF3CH2CHX)2. Where X = CO2CH3 trimeric products were also isolated. With hex-1-yne, electrolysis of trifluoroacetic acid gave a mixture of Z- and E-CF3CHCHC4H9 and E-CF3CHC(CF3)C4H9. In contrast cyclopentene produced only cyclopentyl trifluoroacetates.