Synthesis and electrocatalytic activity of phosphorus-doped carbon xerogel for oxygen reduction

Abstract

The electrocatalyst for oxygen reduction reaction (ORR) plays an important role in determining the performance, cost and durability of fuel cells and metal–air batteries. In this study, low-cost and highly active phosphorus (P)-doped carbon xerogel electrocatalyst for the ORR was facilely synthesized. The catalytic activity of P-doped carbon xerogel for the ORR in 0.1M KOH solution has been studied by using a rotating ring-disk electrode (RRDE) technique. The RRDE results show that P-doped carbon xerogel exhibits excellent catalytic activity for the ORR and long-term stability in basic media. The ORR on P-doped carbon xerogel with optimized amount of P mainly favors a direct four electron pathway. The high electrocatalytic activity and durability of P-doped carbon xerogel are primarily attributed to the P-doping in the carbon lattice. Furthermore, the amount of P incorporated into carbon instead of the specific surface area of the P-doped carbon xerogel is found to play a critical role in the ORR activity enhancement and the ORR pathway modification.