2,2,6,6-Tetramethylpiperidinyl-N-oxyl (TEMPO) mediated electrocatalytic oxidation toward ethylene glycol was investigated as a function of electrolyte (aqueous carbonate buffer solution of pH 9.6 and dichloromethane solution with 2,6-lutidine as the base) by cyclic voltammetry and chronoamperometry. Both half-wave potentials and potential separations of electrochemical oxidation of TEMPO in these two electrolytes show differently. Electrocatalytic oxidation of ethylene glycol mediated by TEMPO was firstly reported here, it was observed the onset potential of this electrocatalytic oxidation reaction in dichloromethane solution is larger than that in carbonate buffer solution, moreover, electrocatalytic oxidation rate constant is calculated from chronoamperograms to be 1.63 x 10(3) L.mol(-1)s(-1) in carbonate aqueous buffer solution, which is forty times as large as that in dichloromethane solution. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.