(Invited) Non-Precious Metal Catalysts with Designed Nanostructures and Controlled Active Sites for Oxygen Reduction Reaction in Fuel Cells

Abstract

In the low temperature fuel cells, it is of great importance to overcome a sluggish oxygen reduction reaction (ORR) by employing the highly effcient electrocatalysts. Due to high cost of the representative Pt based catalysts, it is highly required to develop non-precious metal or metal-free catalysts with high perforamance. In this sense, we developed N,P co-doped large pore sized ordered mesoporous carbons with high activity for ORR. A large pore sized N, P co-doped ordered mesoporous carbon with precisely controlled doping site position exhibited a remarkable on-set potential and produced 70% of the maximum power density obtained using Pt/C. We also developed an ordered mesoporous Fe/N/C catalyst for oxygen reduction reaction in fuel cells. By simple ‘one-pot’ process, we combined two necessary factors for the high performance of Fe/N/C catalyst in cathode of practical-level fuel cell. The ORR kinetic activity of the single Fe-Nx/C active site was increased by a new and versatilely applicable strategy. The incorporated electron withdrawing/donating functionalities changed the strength of the electronic effect, resulting in the change of ORR activity.