Electrooxidations alkali

Formation of the P—N bond has been observed when the cross-coupling of dialkylphosphites (59) with amines (60) proceeds by an iodo cation [I]+-promoted electrooxidation, affording N-substituted dialkylphosphor-amidates (61) (Scheme 22) [76]. Lack of alkali iodide in the electrolysis media results in the formation of only a trace of (61), indicating that the iodide plays an important role in the P—N bond-forming reaction. In contrast, usage of sodium bromide or sodium chloride brings about inferior results since the current drops to zero before the crosscoupling reaction is completed. 

A lot of papers have been addressed to the methanol oxidation on Pt-Ru catalyst in acidic media, and excellent reviews have been done by Spendelow et al. [24] and Petrii [25]. Conversely, few works have been addressed to the MOR on Pt-Ru catalysts in alkali media. Firstly, Petrii et al. [26] compared the polarization curves of methanol electrooxidation in an alkaline solution under steady-state conditions... 

The pH of the electrolyte is effective on the reaction kinetics at the individual electrodes and the electrode potential at which oxidation or reduction takes place [26]. Electrolyte is typically a strong acid or a strong base, such as sulfuric acid or potassium hydroxide, which include highly mobile hydronium or hydroxide ions, respectively [20]. Typically, operation of fuel cell in alkaline media can develop the electrooxidation of the catalyst-poisoning carbon monoxide species on the anode and the kinetics of ORR is improved at the cathode [26]. However, in membrane-based fuel cells, due to the potential of carbonate formation resulting in clogging the membrane, the long-term stability is restricted and limits the use of these alkali-compatible membranes for liquid fuel cell operations [26]. 

Among the most familiar electrosynthetic reactions involving the oxidation of a metal center in a coordination compound is the conversion of alkali metal hexacyanoferrates(II) to the corresponding hexacyanoferrates(III). When the electrolysis is carried out in a divided cell equipped with diaphragm, the electrooxidation is practically quantitative. In a review of studies of the oxidation of [Fe(CN)6] it was noted s that the rate of oxidation of the hexacyanoferrate(II) anion depends on a large number of factors, including the current density, the concentration of the complex in solution, the electrode material, the temperature, and the pH of the solution. 

---