Premium
Nitrogen‐Doped Carbon Activated in Situ by Embedded Nickel through the Mott–Schottky Effect for the Oxygen Reduction Reaction
Author(s) -
Chen Teng,
Guo Siqi,
Yang Jie,
Xu Yida,
Sun Jie,
Wei Dali,
Chen Zhaoxu,
Zhao Bin,
Ding Weiping
Publication year - 2017
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201700834
Subject(s) - catalysis , carbon fibers , heteroatom , materials science , inorganic chemistry , nickel , chemical engineering , chemistry , composite number , organic chemistry , composite material , metallurgy , ring (chemistry) , engineering
The development of low‐cost non‐precious‐metal electrocatalysts with high activity and stability in the oxygen reduction reaction (ORR) remains a great challenge. Heteroatom‐doped carbon materials are receiving increased attention in research as effective catalysts. However, the uncontrolled doping of heteroatoms into a carbon matrix tends to inhibit the activity of a catalyst. Here, the in situ activation of a uniquely structured nitrogen‐doped carbon/Ni composite catalyst for the ORR is demonstrated. This well‐designed catalyst is composed of a nitrogen‐doped carbon shell and embedded metallic nickel. The embedded Ni nanoparticles, dispersed on stable alumina with a high specific surface area for protecting them from agglomeration and in an unambiguous composite structure, are electron‐donating and are shielded by the nitrogen‐doped carbon from oxidation/dissolution in harsh environments. The electronic structure of the nitrogen‐doped carbon shell is modulated by the transfer of electrons at the interface of nitrogen‐doped carbon–Ni heterojunctions owing to the Mott–Schottky effect. The electrochemically active surface area result implies that the active sites do not relate to Ni directly and the enhanced catalytic activity mainly arises from the modulation of nitrogen‐doped carbon by nickel. XPS and theoretical calculations suggest that the donated electrons are transferred to pyridinic N primarily, which ought to enhance the catalytic activity intrinsically. Benefiting from these transferred electrons, the half‐wave potential of the nitrogen‐doped carbon/Ni composite catalyst is 94 mV positively shifted compared to the Ni‐free sample.