Dopant–free edge–rich mesoporous carbon: Understanding the role of intrinsic carbon defects towards oxygen reduction reaction

Two-Dimensional Polyphosphazene Nanosheet-Derived N,P Doubly Doped Carbon Nanotubes for Electrocatalytic Oxygen Reduction

“…As the four-electron process provides high efficiency in energy conversion during the ORR process, this is one of the purposes of designing oxygen electrode catalysts for fuel cells . The optimized CNT@HCCP-TAPT-COP­(1/1)-800 offers a rather high n of 3.97 for the ORR, which outperforms many carbon catalysts, such as N-doped catalysts (NGS4-900, n = 3.9), N,P-doped catalysts (N,P-HGFs-1000, n = 3.7; C-PCTNB@CNTs, n = 3.9), and defect-tailored catalysts (E-MC-1000, n = 3.8). Thus, the optimum CNT@HCCP-TAPT-COP­(1/1)-800 could be ranked among the top metal-free N,P codoped carbon catalysts for the electrochemical ORR (see Table S3 in the Supporting Information).…”

Mesoporous carbon-based materials and their applications as non-precious metal electrocatalysts in the oxygen reduction reaction

“…Nevertheless, it is evident that some of best ORR activity is seen with N doped MC that has additional large pores [103,124] highlighting not only the influence of defects but also the important role of diffusion within the porous structures. In addition to the defects introduced by doping with heteroatoms, intrinsic carbon defects, such as edge defects and sp 3 -type carbon, can also promote the ORR [125,126].…”

“…Some of these conflicting variations may be due to the nature of the M-N x sites, with different levels of M-N 2 and M-N 4 , altering the adsorption of *OOH. The presence of intrinsic carbon defects, which depend on the synthetic approaches used in the fabrication of the MCs, may also alter the nature of the ORR [125,126]. Furthermore, these transition metal modified and nitrogen doped carbon-based electrocatalysts have been shown to produce water from the indirect oxygen reduction reaction, which involves two parallel reactions, the so called 2 + 2 reduction process, with H 2 O 2 as an intermediate, Eqs.…”