Soo Hong Lee1,2, Jiheon Kim1,2, Dong Young Chung1,2, Ji Mun Yoo1,2, Hyeon Seok Lee1,2, Min Jeong Kim1,2, Bongjin Simon Mun3, Soon Gu Kwon1,2, Yung-Eun Sung1,2, Taeghwan Hyeon1,2. 1. Center for Nanoparticle Research , Institute for Basic Science (IBS) , Seoul 08826 , Republic of Korea. 2. School of Chemical and Biological Engineering, and Institute of Chemical Processes , Seoul National University , Seoul 08826 , Republic of Korea. 3. Department of Physics & Photon Science , Gwangju Institute of Science and Technology , Gwangju 61005 , Republic of Korea.
Abstract
The effect of porous structures on the electrocatalytic activity of N-doped carbon is studied by using electrochemical analysis techniques and the result is applied to synthesize highly active and stable Fe-N-C catalyst for oxygen reduction reaction (ORR). We developed synthetic procedures to prepare three types of N-doped carbon model catalysts that are designed for systematic comparison of the porous structures. The difference in their catalytic activity is investigated in relation to the surface area and the electrochemical parameters. We found that macro- and mesoporous structures contribute to different stages of the reaction kinetics. The catalytic activity is further enhanced by loading the optimized amount of Fe to prepare Fe-N-C catalyst. In both N-doped carbon and Fe-N-C catalysts, the hierarchical porous structure improved electrocatalytic performance in acidic and alkaline media. The optimized catalyst exhibits one of the best ORR performance in alkaline medium with excellent long-term stability in anion exchange membrane fuel cell and accelerated durability test. Our study establishes a basis for rationale design of the porous carbon structure for electrocatalytic applications.
The effect of porous structures on the electrocatalytic activity of N-doped n class="Chemical">carbon is studied by using electrochemical analysis techniques and the result is applied to synthesize highly active and stable Fe-N-C catalyst for oxygen reduction reaction (ORR). We developed synthetic procedures to prepare three types of N-doped carbon model catalysts that are designed for systematic comparison of the porous structures. The difference in their catalytic activity is investigated in relation to the surface area and the electrochemical parameters. We found that macro- and mesoporous structures contribute to different stages of the reaction kinetics. The catalytic activity is further enhanced by loading the optimized amount of Fe to prepare Fe-N-C catalyst. In both N-doped carbon and Fe-N-C catalysts, the hierarchical porous structure improved electrocatalytic performance in acidic and alkaline media. The optimized catalyst exhibits one of the best ORR performance in alkaline medium with excellent long-term stability in anion exchange membrane fuel cell and accelerated durability test. Our study establishes a basis for rationale design of the porous carbon structure for electrocatalytic applications.