In:
Journal of Materials Chemistry A, Royal Society of Chemistry (RSC), Vol. 9, No. 44 ( 2021), p. 25136-25149
Abstract:
The electrocatalytic oxygen reduction reaction (ORR) to hydrogen peroxide (H 2 O 2 ) by a two-electron pathway is regarded as a green and substitute technique to the anthraquinone method. However, an important challenge in H 2 O 2 electrogeneration is to design selective and economic electrocatalysts. Herein, nitrogen and oxygen self-doped porous carbon (NO/PC) was prepared using low-cost alfalfa as a raw material without nitrogen sources and strong oxidants. NO/PC prepared at 500 °C (NO/PC-500) showed the highest H 2 O 2 selectivity of 85.1%. The H 2 O 2 electrogeneration performance and stability of a composite gas diffusion electrode with NO/PC-500 as an electrocatalyst were significantly improved at high current density by introducing a polytetrafluoroethylene (PTFE) hydrophobic layer. A NO/PC-500 (g) to PTFE binder (mL) ratio of 1 : 3 was selected as an optimal value to fabricate the composite gas diffusion electrode. X-ray photoelectron spectroscopy combined with density functional theory calculations demonstrated that the OOH adsorption energy on most N/O functional groups (graphitic N, the co-doping of graphitic N and C–O–C, and the co-doping of pyrrolic N and C–O–C) in NO/PC was lower than the H 2 O 2 adsorption energy, which promoted the two-electron ORR and reduced H 2 O 2 decomposition. However, the co-doping of pyridine N and C–O–C in NO/PC is not conducive to H 2 O 2 electrogeneration due to the lowest OOH adsorption energy and the highest H 2 O 2 adsorption energy. Overall, these results have offered insights into the potential application of biomass-derived heteroatom-doped porous carbon as an effective electrocatalyst for H 2 O 2 generation.
Type of Medium:
Online Resource
ISSN:
2050-7488
,
2050-7496
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2021
detail.hit.zdb_id:
2702232-8
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