Pyrolyzing cobalt diethylenetriamine chelate on carbon (CoDETA/C) as a family of non-precious metal oxygen reduction catalyst

Using diethylenetriamine ligand, a family of non-precious metal oxygen reduction catalyst is synthesized by pyrolysis of cobalt-diethylenetriamine chelate on carbon at elevated temperature from 600 to 900 degrees C. Cyclic voltammetry results show that pyrolysis temperature plays an important impact on improving catalytic activity and the maximum activity is obtained at 800 degrees C with its peak potential of 719 mV (SHE). For the best catalyst HT800, rotating-ring disk electrode measurement indicates that the number of electrons transferred is 3.80-3.85 at potential of 0.5 V with rotating rates from 100 to 1600 rpm and the catalyst loading of 648 mu g cm(-2). XRD indicates that the cobalt-nitrogen chelate decomposes above 600 degrees C and nanometallic alpha-Co with different sizes is synthesized. Raman indicates that there are more defective sites on the carbon surfaces induced by N doping. Combined XPS data with electrochemical results, it indicates that a higher total N content does not lead to a higher ORR activity. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.