催化作用
材料科学
电池(电)
过渡金属
X射线吸收精细结构
密度泛函理论
碳纤维
电催化剂
氧气
化学工程
金属
无机化学
纳米技术
电极
化学
物理化学
电化学
光谱学
计算化学
有机化学
冶金
复合材料
功率(物理)
工程类
物理
复合数
量子力学
作者
Mengtian Zhang,Hao Li,Junxiang Chen,Fei‐Xiang Ma,Liang Zhen,Zhenhai Wen,Cheng‐Yan Xu
出处
期刊:Small
[Wiley]
日期:2022-07-29
卷期号:18 (34)
被引量:43
标识
DOI:10.1002/smll.202202476
摘要
Abstract Exploring highly active and cost‐efficient single‐atom catalysts (SACs) for oxygen reduction reaction (ORR) is critical for the large‐scale application of Zn–air battery. Herein, density functional theory (DFT) calculations predict that the intrinsic ORR activity of the active metal of SACs follows the trend of Co > Fe > Ni ≈ Cu, in which Co SACs possess the best ORR activity due to its optimized spin density. Guided by DFT calculations, four kinds of transition metal single atoms embedded in 3D porous nitrogen‐doped carbon nanosheets (MSAs@PNCN, M = Co, Ni, Fe, Cu) are synthesized via a facile NaCl‐template assisted strategy. The resulting MSAs@PNCN displays ORR activity trend in lines with the theoretical predictions, and the Co SAs@PNCN exhibits the best ORR activity ( E 1/2 = 0.851 V), being comparable to that of Pt/C under alkaline conditions. X‐ray absorption fine structure (XAFS) spectra verify the atomically dispersed Co‐N 4 sites are the catalytically active sites. The highly active CoN 4 sites and the unique 3D porous structure contribute to the outstanding ORR performance of Co SAs@PNCN. Furthermore, the Co SAs@PNCN catalyst is employed as cathode in Zn–air battery, which can deliver a large power density of 220 mW cm –2 and maintain robust cycling stability over 530 cycles.
科研通智能强力驱动
Strongly Powered by AbleSci AI