Heat-treated 2,2′-bipyridine iron complex supported on polypyrrole-coated carbon for oxygen reduction reaction

Nitrogen-containing non-noble metal catalysts for oxygen reduction reaction (ORR) are prepared by supporting 2,2'-bipyridine iron complex on polypyrrole-coated carbon support followed by pyrolysis at various temperatures (600, 700, 850, and 1000 degrees C). The prepared catalysts and support are characterized by IR, elementary analysis, TEM, and XPS. Revealed is that the contents of pyridinic nitrogen on a catalyst would not be a determining factor for ORR activity. The concentration of pyridinic nitrogen diminishes with the increasing pyrolysis temperature, while the ORR performance is observed to be enhanced with a maximum at 850 degrees C. It is believed that the pyridinic nitrogen added as a precursor should be activated to serve as an active site for ORR, indicating that an increasing pyrolysis temperature is favored to form a highly active site. However, the pyrolysis at too high of temperature (1000 degrees C) turns out to be undesirable due to a considerable loss of active nitrogen. (C) 2011 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.