The influence of non-ionic surfactants on electrosynthesis in extended channel, narrow gap electrolysis cells

It is demonstrated that the addition of a non-ionic surfactant (Triton X-100 or Brij L23) to the electrolyte medium leads to a significant improvement to the current efficiency for the methoxylation of N-formylpyrrolidine in a flow electrolysis cell with a horizontal, extended channel length and narrow interelectrode gap (the Ammonite 8). In the presence of Brij L23, the fractional current efficiency is much improved and approaches 1.0 while maintaining a fractional selectivity of 0.99 at a very high conversion in a single pass. The improvement in current efficiency is ascribed to a decrease in the bubble size of the H2 gas evolved at the counter electrode leading to an enhancement in the mass transport regime in the flow stream through the extended channel with millimetre dimensions. Keywords: Electrolysis, Mass transfer, Gas evolution, Flow reactors, Anodic oxidation, Surfactants