Ingeniously introducing of boron to adjust hetero-atoms and their bonding with cobalt for improving the catalysis of oxygen reduction reaction.

A novel method of introducing boron element was used to prepare a composite catalyst in which cobalt nanoparticles were embedded in N, B, and S-doped carbon matrix (Co-NBSC). This method can significantly retain the nitrogen content in the catalyst by introducing only a small amount of boron. The bonding ability of cobalt to hetero-atoms was also improved. The optimized bonding patterns between heteroatoms and metal-cobalt have further improved the performance of catalyzing the oxygen reduction reaction (ORR). Electrochemical tests show that the Co-NBSC catalyst possesses an onset potential of 0.93 ​V, a half wave potential of 0.84 ​V and a current density of 5.58 ​mA/cm2 as well as excellent stability in an alkaline solution. In addition, Co-NBSC based zinc-air battery exhibited a power density of 121.2 ​mW/cm2 and a discharge stability of more than 30 ​h. The synthesis strategy can provide new ideas for the future development of low cost non-precious metal-carbon catalyst of ORR. Novel method of increasing nitrogen contents through boron, which can effectively to improve the ORR activity. Image 1 • Novel method of increasing nitrogen content via cleverly introducing boron. • This method also promotes the formation of heteroatom-cobalt-carbon bonds. • Increased N-content and optimized bonding patterns improved ORR performances. • Onset potential of ORR was shifted positively and the Tafel slope decreased. [ABSTRACT FROM AUTHOR]