石墨烯
催化作用
热解
材料科学
电化学
碳纤维
氮气
化学工程
化学
氧气
密度泛函理论
兴奋剂
纳米技术
物理化学
电极
有机化学
计算化学
复合数
光电子学
工程类
复合材料
作者
Xiaoran Zhang,Xiao Zhang,Shiyong Zhao,Yun Qiu Wang,Lin Xu,Zhi Qun Tian,Pei Kang Shen,San Ping Jiang
标识
DOI:10.1016/j.electacta.2021.137712
摘要
Tuning active configurations of different nitrogen (N) species and elucidating their influence on the catalytic activity for oxygen reduction reaction (ORR) is important to develop N-doped carbon (N/C) as efficient metal-free catalysts. The challenge is to selectively control the active N sites of N/C. Herein, we approach this challenge by modulating N active species in graphene structured N/C with specific precursors via a one-step pyrolysis process. In this method, 5-aminouracil is selected as the N-containing precursor platform to modulate the pyridinic N (NP), while 2,6-diaminopyridine and 1,3-diaminobenzene are used to modulate graphitic N (NG) and pyrrolic N (NPY), respectively. N/C materials with specific different N configurations such as N/CNP+NG, N/CNP+NP and N/CNP+NPY are successfully synthesized and identified by microstructure and phase characterization. Electrochemical results demonstrate that N/CNP+NG exhibits the best ORR performance, achieving an onset potential (Eonset) of 0.98 V and half-wave potential (E1/2) of 0.86 V vs. RHE, respectively, which is comparable to that obtained on conventional Pt/C. By contrast, N/CNP+NPY exhibits the lowest activity for ORR. Density functional theory (DFT) simulation further validates that the NP+NG configuration produces strong electronic distribution on carbon matrix that leads to high charge and high spin density on surrounding carbon atoms. This work provides a facile approach to design N doped graphene structured carbon materials with active N configurations for ORR.
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