Clarification of Active Sites for Oxygen Reduction Reaction on Silver and Nitrogen Co-Doped Carbon Materials

摘要

The oxygen reduction reaction (ORR) is one of the most important reactions in both fuel cells and metal-air batteries. ORR needs catalysis to lower the electrochemical overpotential for high-voltage output for these technologies and, so far, platinum (Pt) has been the main catalyst of choice. However, as the expensive, traditional Pt/C catalysts are not viable in the long term, much effort has been focused on heteroatom doped and non-precious metal catalysts. Metal-nitrogen co-doped carbon materials have emerged as the main candidates for replacing the platinum-based catalysts. Among these materials, silver and nitrogen co-doped catalysts have proven to exhibit high electrocatalytic activity for the ORR in alkaline media. However, no clear understanding exists about the exact catalytic mechanism and rational design of these catalysts.