Chinese Journal of Catalysis ›› 2018, Vol. 39 ›› Issue (6): 1138-1145.DOI: 10.1016/S1872-2067(18)63078-5

• Articles • Previous Articles    

Simple synthesis of nitrogen-doped carbon spheres as a highly efficient metal-free electrocatalyst for the oxygen reduction reaction

Jinhui Tonga, Wenyan Lia, Lili Bob, Wenhui Wanga, Yuliang Lia, Tao Lia, Qi Zhanga, Haiyan Fanc   

  1. a Key Laboratory of Polymer Materials of Gansu Province, Key Laboratory of Eco-Environment-Related Polymer Materials Ministry of Education, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, Gansu, China;
    b College of Science, Gansu Agricultural University, Lanzhou 730070, Gansu, China;
    c Department of Chemistry, School of Science and Technology, Nazarbayev University, Astana 010000, Kazakhstan
  • Received:2018-04-18 Revised:2018-04-23 Online:2018-06-18 Published:2018-05-16
  • Contact: 10.1016/S1872-2067(18)63078-5
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (21363021, 51302222) and Program for Changjiang Scholars and Innovative Research Team in University (IRT15R56).

Abstract:

In the present work, nitrogen-doped carbon spheres were synthesized through a simple hydrothermal treatment using glucose and melamine as inexpensive carbon and nitrogen sources, respectively. The ratio of melamine to glucose and annealing temperature were optimized. The final optimal sample exhibited a catalytic activity for the oxygen reduction reaction (ORR) that was superior than that of commercial 20%Pt/C in 0.1 mol/L KOH. It revealed an onset potential of -22.6 mV and a half-wave potential of -133.6 mV (vs. Ag/AgCl), which are 7.2 and 5.9 mV more positive than those of the 20%Pt/C catalyst, respectively, as well as a limiting current density of 4.6 mA/cm2, which is 0.2 mA/cm2 higher than that of the 20%Pt/C catalyst. The catalyst also exhibited higher stability and superior durability against methanol than 20%Pt/C. Moreover, ORRs on this catalyst proceed through a more effective 4e- path. The above mentioned superiority of the as-prepared catalyst makes it promising for fuel cells.

Key words: Nitrogen doping, Carbon spheres, Metal-free catalyst, Oxygen reduction reaction