Protic acids homogeneous

Thus far the solvent systems we have discussed are typical protic organic media, such as, for example, water-ethanol mixtures containing an added supporting electrolyte. These solvents are presumably quite homogeneous on a microscopic level. However, a number of solvents have been developed in recent years which are heterogeneous on a microscopic scale. Micellar media are one example of such solvents. The electrochemical reduction of nitrobenzene in aqueous solutions containing polyoxyethylene lauryl ether, a substance known to produce neutral micelles, produces azobenzene (4) even at pH somewhat less than 723. This is apparently the first case of formation of a dimeric product from electrolysis of nitrobenzene (1) in acidic media. Another striking example of this phenomenon... 

Since the two-electron reduction to formic acid or CO requires a lower potential, electrolysis using a multielectron transfer catalyst in aqueous or in low-protic media can be carried out at considerably lower voltages. The simplest electrocatalytic system for CO2 reduction is an electrochemical cell that contains a working electrode, a reference electrode, a homogeneous electrocatalyst, the supporting electro-... 

This chapter focuses on the advantages achieved with different procedures and makes comparative analyses of the synthetic results. Furthermore, despite utility at small scale, the use of Lewis acid/acyl chlorides reagents on an industrial scale is frequently discouraged due to the large amounts of waste produced. Practically, the use of homogeneous Lewis acids in combination with acyl chlorides or anhydrides poses a serious problem for the efficient recovery and disposal of metal oxides and protic inorganic acid by-products. 

---