Nature Communications
·
2024
·Vol. 15
·期 1
·1-10
·
IF 14.7
Yin Shuhu,Chen Long,Yang Jian,Cheng Xiaoyang,Zeng Hongbin,Hong Yuhao,Huang Huan,Kuai Xiaoxiao,Lin Yangu,Huang Rui,Jiang Yanxia,Sun Shigang
Replacement of expensive and rare platinum with metal–nitrogen–carbon catalysts for oxygen reduction reactions in proton exchange membrane fuel cells is hindered by their inferior activity. Herein, we report a highly active iron-nitrogen-carbon catalyst by optimizing the carbon structure and coordination environments of Fe-N 4 sites. A critical high-temperature treatment with ammonium chloride and ammonium bromide not only enhances the intrinsic activity and density of Fe-N 4 sites, but also introduces numerous defects, trace Br ions and creates mesopores in the carbon framework. Notably, surface Br ions significantly improve the interaction between the ionomer and catalyst particles, promoting ionomer infiltration and optimizing the O 2 transport and charge transfer at triple-phase boundary. This catalyst delivers a high peak power density of 1.86 W cm −2 and 54 mA cm −2 at 0.9 V iR-free in a H 2 -O 2 fuel cells at 80 °C. Our findings highlight the critical role of interface microenvironment regulation.
研究领域:
电化学
·
催化
·
能源材料
·
燃料电池
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Energy Chemistry
·
2026
·
IF 15.6
Zihan Wang,Tianqi Song,Xue Wang,Yanlong Ren,Yanli Zeng,Jingyuan Ma,Mingxing Wu,Jianing Guo
Covalent organic polymers (COPs) are regarded as prospective catalysts toward the oxygen reduction reaction (ORR) owing to their tailorable skeleton structures and precisely identifiable catalytic sites. Nevertheless, their intrinsically low conductivity and insufficiently exposed active sites constitute critical bottlenecks that greatly restrict ORR catalytic performance and cycling durability in practical applications. Herein, we propose a structural engineering strategy to construct high-efficiency and durable composite electrocatalysts (COP@HPC) with well-defined Fe-N 4 active sites, which is achieved by integrating a fully π-conjugated iron-phthalocyanine-based COP with a three-dimensional hierarchically porous carbon substrate via strong π-π interactions. The interconnected conductive network can effectively accelerate electron transfer and mass transport kinetics, while the conjugated COP offers atomically dispersed Fe-N 4 active sites with tunable electronic properties. Consequently, COP@HPC composite catalyst delivers outstanding electrocatalytic performance toward ORR with a high half-wave potential ( E 1/2 ) of 0.92 V, which is superior to that of the composite supported on a dense carbon substrate. In-situ Raman and density functional theory (DFT) calculations confirm the dynamic evolution of ORR intermediates on π-π modulated Fe-N 4 sites, verifying that strong interfacial coupling optimizes intermediate adsorption energy and reduces the rate-determining step energy barrier. When integrated into a liquid zinc-air battery, COP@HPC displays an excellent power density of 227 mW cm −2 and retains stable cycling for over 1000 h (1538 cycles). This work establishes a universal structural engineering methodology for developing high-efficiency single-atom electrocatalysts. A π-π assembly non-pyrolysis strategy is developed to synthesize COP@HPC single-atom electrocatalysts with well-defined Fe-N 4 sites. The 3D porous conductive matrix facilitates electron/mass transfer, while interlayer π-π interactions lower the ORR rate-determining barrier. Download: Download high-res image (189KB) Download: Download full-size image
✓ 已验证
DOI
高影响因子
MICROCHIMICA ACTA
·
2025
·Vol. 192
·期 7
·1-11
·
IF 5.3
Zhang Guo-Qi,Long Xia,Shi Yu-Han,Wu Wei,Zhou Xin-Yue,Jiang Wen-Cai,Li Tian-Qi,Xiang Wen-jing,Liu Wei-Ping,Zhao Yan
Herein, we present a proof-of-concept investigation into the assessment of the laccase-like activity of covalently bonded carbon environments connected to Fe-N 4 sites, using the closed π conjugated phthalocyanine-based intrinsic covalent organic polymers (COP) with well-designed structures. Based on the theoretical prediction and experimental implementation, the impact of the covalent-bonded carbon matrix on the laccase-like activity of COP-X (X represents the degree of conjugation) was systematically investigated. Further calculation results by density functional theory showed that the strongest laccase-like catalytic activity of COP-2 may be due to the facile desorption of catalytic intermediates, and the laccase-like catalytic mechanism of COP-2 nanozymes was also deeply understood. As anticipated, the utilization of COP-2 nanozymes with laccase-like activity enabled the achievement of excellent sensitivity for monitoring epinephrine in human serum. In addition, the COP-2 nanozymes also facilitate the detection and degradation of phenolic pollutants present in the environment. This finding presents a novel perspective for the rational design of high-performance laccase-like iron based nanozymes, and also lays the foundation for clarifying the origin of the laccase-like activity of nanozymes. Graphical
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBON
·
2019
·
IF 7.466
Xilong Wang,Jian Du,Qinghua Zhang,Lin Gu,Lijuan Cao,Han-Pu Liang
It is highly desirable to develop low-cost and high-efficient non-precious electrocatalysts for oxygen reduction reaction (ORR) in attempt to replace the expensive Pt based catalysts for fuel cells and metal-air batteries . Herein, a novel, facile and cost-effective strategy is reported to in situ synthesize isolated single iron (Fe) atoms anchored on nitrogen doped carbon (Fe-ISA/NC) with renewable Auricularia auricular-judae as the biomass precursor. The best performing Fe-ISA/NC exhibits high specific surface area of 1107 m 2 g −1 and excellent activities for ORR in 0.1 M KOH, in terms of an onset potential of 1.0 V vs. RHE and a half-wave potential of 0.89 V vs. RHE, surpassing that of Pt/C and most reported non-precious metal catalysts . Furthermore, superior methanol tolerance and outstanding stability are observed. X-ray absorption fine structure (XAFS) analysis and density functional theory (DFT) calculations reveal that the Fe-N 4 moieties together with pyrrolic-N are responsible for the enhanced catalytic performance for ORR.
研究领域:
材料科学
·
电化学
·
可再生能源
·
催化
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）