In an attempt to improve the electrocatalytic performance of non-precious metal CoDETA/C catalyst for the oxygen reduction reaction (ORR) both in acid and alkaline media, herein, four types of post-treatment, including acid leaching and its re-pyrolysis, alkaline leaching and its re-pyrolysis are investigated. XRD indicates that there is a dissolution of nanometal Co after leaching in acid electrolyte and the formation of Co(OH)(2) in alkaline electrolyte. Raman shows that the degree of defect decreases after post-treatment. Electrochemical results display that post-treatment of leaching and its re-pyrolysis have a positive influence on the ORR electrocatalytic activity of CoDETA/C catalyst both in acid and alkaline electrolytes. In special, acid leaching and acid leaching combined with re-pyrolysis is a wise way to increase the electrocatalytic performance of CoDETA/C catalyst in acid and alkaline electrolyte, respectively. Application of leaching and its re-pyrolysis is thus revealed to be useful for improving the ORR electrocatalytic performance of CoDETA/C catalyst. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.