Nitrogen modified carbon based catalysts for the oxygen reduction reaction (ORR) were synthesized using three different types of carbon, carbon black (CB), carbon nanotube (CNT) and platelet carbon nanofiber (P-CNF) with nitrogen containing organic precursors. The relationship between the ORR activity and the carbon nanostructure was explored using various electrochemical and physical characterization methods. It was found that the ORR activity was affected by the type and content of the nitrogen functional group instead of the carbon surface area. The formation of nitrogen functional group, in turn, strongly depends on the carbon nanostructure. Unlike the basal plane, the edge plane exposure provides the appropriate geometry for the nitrogen incorporation into carbon structure, resulting in high nitrogen content and high pyridinic-N and graphitic-N content, providing an active site for ORR. Therefore, the P-CNF based catalyst with the highest edge plane exposure has the highest ORR activity despite having the smallest surface area.
Bibliographical noteFunding Information:
This work was jointly supported by the National Research Foundation of Korea ( NRF-2009-C1AAA001-0092926 ), the Ministry of Education, Science and Technology and the Energy & Resource Recycling Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), which is funded by the Korean Ministry of Knowledge Economy ( 2008k01600 ).
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Condensed Matter Physics
- Energy Engineering and Power Technology