Enhanced Electrocatalytic Activity of Activated Carbons for Oxygen Reduction Reaction By Boron and Nitrogen Co-Doping in Carbon Lattices

The effect of boron and nitrogen (BN) insertion to carbon materials on oxygen reduction reaction (ORR) in fuel cells was investigated. BN-doped porous carbons were prepared by utilizing commercial activated carbon (AC), boric acid, and urea as C, B, and N precursors, respectively. Simple mixing of the precursors with AC and subsequent annealing were used to synthesize the carbon materials with respect to varying temperatures (700^oC, 850^oC, and 1000^oC) and mixing ratios (10:1, 1:1). The synthesized carbon materials were structurally analyzed and used as electrocatalysts for ORR to investigate the electrocatalytic activities. According to the structural analysis results, the BN co-doped AC shows much higher doping contents than the B or N single-doped AC despite the use of the same amounts of doping precursors as in the single doping case. The electrochemical analysis indicates that higher B or N doping contents enhance the level of ORR activity with the four-electron pathway, especially for BN co-doping case due to the formation of B-N-C bonds. The result shows potentials of BN co-doped activated carbon as a cost-effective alternative for oxygen reduction reaction in fuel cell.