Anodic Processes of Acetate Ion in Methanol and in Glacial Acetic Acid at Various Anode Materials

Abstract

The anodes used in this study were platinum, gold, palladium, lead dioxide, and graphite. The normal Kolbe process, the formation of ethane (and methane) and carbon dioxide, can be realized at a potential higher than 2.0v (vs. SCE) in both methanol and glacial acetic acid. In methanol, only platinum and gold seem to be suitable for realizing the process. In glacial acetic acid, however, all of the anodes except graphite can be used successfully for the same process. Another process, the formation of methyl acetate, occurs in both solvents at graphite in the potential range 1.4–2.0v. A side reaction observed in methanol at palladium, graphite, and lead dioxide was the formation of formaldehyde (and methyl formate in case of lead dioxide) which occurs at potentials as low as 1.2v.

Understanding the reaction mechanism of Kolbe electrolysis on Pt anodes

“…In the limit of anhydrous conditions (pH2O = 0), there is no inflection zone, as there is no competition between OER with the Kolbe reaction in this extreme case. This conclusion is also in line with previous observations that the Kolbe synthesis proceeds with optimal selectivities in nonaqueous media, e.g., in pure carboxylic acid solutions 41,62 , methanol 63,64 or other solvents 16 .…”

An Electrolytic System That Uses Solid‐Supported Bases for In Situ Generation of a Supporting Electrolyte from Acetic Acid Solvent

“…Acetonitrile was then added as a co‐solvent and the cyclic voltammogram of 0.1 M 2 /AcOH/MeCN was measured. As shown in Figure 1 b, both an oxidation wave for AcO − at about 2.1 V vs. SCE and a reduction current for H + were observed 9. Therefore, it is clear that solid‐supported bases cause acetic acid to dissociate into acetate anions and protons, and the resulting protons seem to act as the main carrier of the electronic charge.…”

First-Principles Investigation of the Unique Role of Anode Surfaces in Organic Electrochemical Reactions

“…Organic electrochemical reactions are frequently used for academic and industrial applications because of their mild conditions, high efficiency, and environmental friendliness. − There are many factors that can influence the reaction processes, leading to different reaction paths with distinct products and efficiencies. − For example, the electrochemical oxidation of carboxylic acid will undergo two main, completely different reaction paths, the Kolbe pathway (usually named the Kolbe reaction) and the non-Kolbe pathway, to generate different products under the influence of different experimental conditions. Electrochemists have conducted extensive experimental studies to realize various reaction paths with different mechanisms via altering the experimental conditions in Kolbe reactions.…”