Homogeneous electrolysis processes, effect

Kolbe electrolysis also allows some comparisons with analogous homogeneous reactions with regard to dimerization, substitution, or addition reactions of the generated radicals. Photolytic or thermal decarboxylation of diacylperoxides is a source of alkyl radicals similar to those afforded by the Kolbe electrolysis. The anodic oxidation of propionate has been compared with the thermal decomposition of dipropionyl peroxide [28]. Examination of the yields shows that reaction between radicals is favored in the electrochemical process, whereas in peroxide decomposition hydrogen atom abstraction from the solvent or the substrate occurs to a higher extent. This illustrates the effect of the higher radical concentration at the electrode. 

Elementary processes of water electrolysis at mercury [268-271] and at platinum [272] electrodes have also been studied in autoclaved aqueous solution. Diffusion coefficients [235, 236] and transfer coefficients [273] have been determined in pressurised aqueous medium. The influence of the phenomenon of thermodiffusion (Soret effect) was followed [217]. This effect generally plays a role if regions of different temperature inside a homogeneous electrolyte phase occur. This is not typical for isothermal systems considered here. In non-isothermal cells (see later below), it should be taken into account. 

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