Electrochimica Acta, Vol.55, No.28, 8808-8814, 2010
Liquid vertical bar liquid biphasic electrochemistry in ultra-turrax dispersed acetonitrile vertical bar aqueous electrolyte systems
Unstable acetonitrile vertical bar aqueous emulsions generated in situ with ultra-turrax agitation are investigated for applications in dual-phase electrochemistry Three modes of operation for liquid vertical bar liquid aqueous-organic electrochemical processes are demonstrated with no intentionally added electrolyte in the organic phase based on (i) the formation of a water-soluble product in the aqueous phase in the presence of the organic phase (ii) the formation of a product and ion transfer at the liquid I liquid-electrode triple phase boundary and (iii) the formation of a water-insoluble product in the aqueous phase which then transfers into the organic phase A three-electrode electrolysis cell with ultra-turrax agitator is employed and characterised for acetonitrile I aqueous 2 M NaCl two phase electrolyte Three redox systems are employed in order to quantify the electrolysis cell performance The one-electron reduction of Ru(NH3)(6)(3+) in the aqueous phase is employed to determine the rate of mass transport towards the electrode surface and the effect of the presence of the acetonitrile phase The one-electron oxidation of n-butylferrocene in acetonitrile is employed to study triple phase boundary processes Finally the one-electron reduction of cobalticenium canons in the aqueous phase is employed to demonstrate the product transfer from the electrode surface into the organic phase Potential applications in biphasic electrosynthesis are discussed (C) 2010 Elsevier Ltd All rights reserved
Keywords:Triple phase boundary;Electrosynthesis;Electrochemistry;Phase transfer catalysis;Ion transfer;Voltammetry;Ion extraction;Cobaltocene;Ferrocene;Ultrasound