Emergence of convective instability in the process of electroreduction of a polytetrafluoroethylene suspension in a tetraalkylammonium salt solution in dimethyl sulfoxide on the surface of a mercury-pool cathode

The electroreduction of mechanically activated solid particles of a polytetrafluoroethylene suspension on a mercury-pool cathode in DMSO solutions containing (C₂H₅)₄NClO₄ is investigated visually and by taking polarization measurements. It is established that the process is accompanied by the emergence of a convective instability, which manifests itself in a spontaneous ordered motion of solid particles in two mutually opposite vertical directions and in the fluctuations of electric current. The assumption is put forth about the formation, in these conditions, of spatial (cellular) and space-time dissipative structures. The basis for the above phenomena is a nonuniform distribution of local values of the current density and potential at the surface of the mercury-pool cathode, which gives rise to vertical and horizontal gradients of the temperature of the liquid phases and the interfacial tension of mercury.