Electrosynthesis in systems of two immiscible liquids and a phase transfer catalyst. I. The anodic cyanation of naphthalene

Totten

Aktan

1988

It was demonstrated that the principles of ion pairing could be used to predict the effect of a quaternary ammonium salt on the rate of electrodeposition of several metals. In agreement with prediction the cationic surfactant, in general, appreciably increased the limiting current, the current efficiency, and the percentage composition in alloys of metals deposited from negative ions in solution while decreasing slightly the same factors for metals deposited from positive ions in solution. It was also shown that there are predictable situations in which the ion paired acceleration would not be observed when expected. Those situations are: (1) processes not limited by the rate of adsorption; (2) processes in which the rate is limited by reaction with a species different from the predominant negatively charged species; and (3) processes in which a film is formed on the electrode.

Section: Discussionmentioning

confidence: 99%

Ion Pairing as a Mechanism of Action of Additives in Electrodeposition

Totten

Aktan

1988

“…Motoo et aL have tried to design the structure of the catalyst layer using two kinds of carbon support with different particle size (6). They have also studied the effect of the PTFE content in the catalyst layer on the acid absorption and electrode performance (7). However, the effect of the heat-treatment temperature of the catalyst layer has not been reported up to date.…”

Section: Introductionmentioning

confidence: 99%

“…A study was initiated on the use of ion-pairing as a different method of controlling the composition of electrodeposited alloys. Ion-pairing is a widely used technique for accelerating many reactions in organic (2,3), electroorganic (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19), and electro-inorganic chemistry (13,14,(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30). In all of these applications, the reactions are accelerated by extracting an ion from a high dielectric constant medium (an aqueous system) to a low dielectric constant medium [a nonpolar organic system or the electrode interface (31)] by the formation of an ion-pair that is more stable in the low dielectric constant medium.…”

mentioning

confidence: 99%

Ion Pairing as a Method of Controlling the Composition of Electrodeposited Alloys

Darlington

Fierro

1986

A study was made of the possibility of controlling the composition of electrodeposited alloys by the use of noncomplexing ion‐pairing salts. It was shown both voltammetrically and by analysis of electrodeposits that the addition of ion‐pairing cations increased the rate of deposition of tin significantly (because of ion‐pairing with the negative stannite or stannate ion) and slightly decreased the rate of deposition of the positively charged copper. As a consequence of this, the addition of tetrabutylammonium perchlorate increased the ratio of tin to copper in the deposit. The lowering of the dielectric constant of the solution by addition of tert‐butyl alcohol increased the ion‐pairing and, thus, increased this effect. Similarly, it was shown that the quaternary salt increased the current efficiency for deposition of tin and slightly decreased the current efficiency for deposition of copper.

“…In studies of the ability of quaternary ammonium salts to increase the yields obtained in anodic oxidations in emulsion and micelle systems, it has been postulated that, in addition to aiding in the dissolution of the organic compounds in aqueous systems, the quaternary salts: (i) act as phase transfer or micelle catalysts (1)(2)(3)(4)(5)(6)(7)(8), and (ii) alter the electrode characteristics by formation of a surface film (9)(10)(11)(12)(13)(14)(15)(16)(17). This film has been concluded to be an oxidized form of the surfactant rather than the commonly observed platinum oxide films, since its potential of formation is significantly more anodic than that of the oxides (11,17).…”

mentioning

confidence: 99%

The Effect of Quaternary Ammonium Salts on Electro‐oxidation of Benzhydrol

Jimbo

1987

A study was made of the effect of tetra‐alkylammonium salts on the anodic oxidation of benzhydrol using potential pulse and galvanostatic pulse techniques. The results of the studies were in agreement with the interpretation that, in addition to solubilization effects, the primary cause of the increased yields is the formation of a film on the surface, which excludes side reactions with water. Potential pulse studies were in agreement with the previous conclusion that this film undergoes reorganization at a potential around −0.6V vs. SCE. The galvanostatic pulse studies showed that it requires a cathodic current pulse to destroy this film in a short time.