CHEMICAL ENGINEERING JOURNAL
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2021
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IF 13.273
Meng Li,Zilong Li,Xiaolong Yu,Yinlong Wu,Cehui Mo,Mi Luo,Ligui Li,Shaoqi Zhou,Qiming Liu,Nan Wang,King Lun Yeung,Shaowei Chen
Development of low-cost, high-performance catalysts for the effective degradation of organic dyes is of both fundamental and technological significance for environmental remediation. Herein, FeN 4 -doped carbon nanotubes exhibit a remarkable catalytic activity towards the degradation of acid orange 7 (AO7) in the presence of peroxymonosulfate (PMS). This is accounted for by the abundant well-dispersed FeN 4 sites and appropriate adsorption energy. Radical quenching experiments and electron paramagnetic resonance measurements suggest that singlet oxygen is the main reactive oxygen species. 57 Fe Mossbauer spectroscopy measurements show that the FeN 4 moieties contain multiple spin states, and in conjunction with density functional theory calculations, confirm that FeN 4 with a low/medium spin state serves as the key sites for PMS activation and hence AO7 degradation. Results from this study highlight the critical role of spin states in FeN 4 in the generation of singlet oxygen for effective degradation of organic pollutants.
研究领域:
环境科学
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材料科学
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催化化学
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DOI
高影响因子
ACS Catalysis
·
2021
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IF 13.084
Yiyang Lin,Kang Liu,Kejun Chen,Yan Xu,Hongmei Li,Junhua Hu,Ying-Rui Lu,Ting-Shan Chan,Xiaoqing Qiu,Junwei Fu,Min Liu
Atomically dispersed FeN4 catalysts have been considered as potential materials to replace Pt-based catalysts for the oxygen reduction reaction (ORR), but they often suffer from sluggish O2 activation kinetics due to the symmetrical charge distribution. Herein, we introduce external N, including pyrrolic-N (PN) and graphitic-N (GN), as an electron acceptor near FeN4 to regulate its charge distribution and improve its ORR activity. Theoretical calculations reveal that introduction of PN evokes much enhanced electron redistribution and local electrical field on the Fe site compared with those observed with GN introduction and the pristine one. Synchrotron X-ray absorption spectroscopy and X-ray photoelectron spectroscopy validate the positive charge accumulation of Fe in the FeN4 site induced by introducing PN. Thus, the obtained FeN4-PN exhibits a great performance for ORR in 0.1 M KOH with a remarkable half-wave potential of 0.91 V versus reversible hydrogen electrode, as well as a Tafel slope of 58 mV decade–1. This work provides a guide to improve the catalytic performances of single-atom catalysts by introducing charge-redistribution sites.
研究领域:
材料科学
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催化化学
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能源科学
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DOI
高影响因子
ChemCatChem
·
2021
·Vol. 13
·期 11
·2683-2690
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IF 5.686
Xinxin Jin,Yan Xie,Junhong Fu,Chaoyue Zhao,Yinghao Xu,Yang Lv,Bingsen Zhang,Keju Sun,Rui Si,Jiahui Huang
Graphical ORR : We fabricated a FeSA/HNPC electrocatalyst with well atomically dispersed FeN 4 species. DFT calculations uncovered that the single-atomic FeN 4 sites within FeSA/HNPC electrocatalyst present in the configurations of pyrrole-N 4 −Fe are more favorable than those of pyridine-N 4 −Fe for boosting ORR performances. Atomically dispersed Fe−N−C electrocatalysts have displayed excellent catalytic performances towards the oxygen reduction reaction (ORR), while the identification of the genuine active sites remains a challenge. Herein, we report a Fe−N−C electrocatalyst of FeSA/HNPC featuring single-atomic FeN 4 sites on hierarchically N-doped porous carbon (HNPC), which shows a very competitive ORR activity in alkaline solution even at a low electrocatalyst loading of 0.2 mg cm −2 on the working electrode. A comparison of energy barriers in ORR reveals that the single-atomic FeN 4 active sites in FeSA/HNPC existing in the form of pyrrole-N 4 −Fe is more favorable than that of pyridine-N 4 −Fe for the enhanced ORR activity. Understanding the nature of FeN 4 active sites will greatly benefit the design of Fe−N−C electrocatalysts with highly effective ORR performances.
研究领域:
材料科学
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电化学
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理论计算
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DOI
高影响因子
Nano-Micro Letters
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2023
·Vol. 15
·期 1
·1-17
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IF 26.6
Chen Shengmei,Liang Xiongyi,Hu Sixia,Li Xinliang,Zhang Guobin,Wang Shuyun,Ma Longtao,Wu Chi-Man Lawrence,Zhi Chunyi,Zapien Juan Antonio
The strong interaction between Ti 3 C 2 S x and FeN 4 species induces the central metal Fe(II) in FeN 4 species with intermediate spin state transferred to high spin state, in which the latter is favorable to initiate the reduction of oxygen.
This strong interaction induces a remarkable Fe 3 d electron delocalization with d band center upshift, boosting oxygen-containing groups adsorption on FeN 4 species and oxygen reduction reaction kinetics.
The resulting FeN 4 –Ti 3 C 2 S x with FeN 4 moieties in high spin state exhibits high half-wave potential of 0.89 V vs. RHE and high limiting current density of 6.5 mA cm −2 , enabling wearable zinc–air battery showing a good discharge performance with a maximum power density of 133.6 mW cm −2 .
研究领域:
材料科学
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电化学
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能源存储与转换
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2024
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IF 8.1
Guangchao Li,Youbin Zheng,Hao Guo,Ze Li,Guohao Zhu,Liang Dong,Xin Liu,Jianbing Zang
In this paper, we present a method to enhance the stability of Fe–N–C electrocatalysts, known for their significant oxygen reduction reaction (ORR) activity and positioned as promising alternatives to commercial noble metal-based catalysts. Despite the favorable ORR activity, Fe–N–C suffers from inadequate stability in acidic media, primarily attributed the loss of active FeN 4 sites resulted from Fe-demetalation. However, recent investigation reveals that pyridine N exhibits remarkable stability in retaining Fe atoms. To address this, we achieved a high proportion of pyridine N doping in carbon nanofibers through a process involving nano-SiO 2 shell coating and electrospinning. The nano-SiO 2 shell coating method demonstrates efficacy and versatility in transforming pyrrole-type FeN 4 into pyridine-type FeN 4 , irrespective of the origin material being trivalent or divalent Fe, whether organic or inorganic.
研究领域:
电化学
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材料科学
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催化
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产品关联
DOI
高影响因子
Nano Energy
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2020
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IF 16.602
Jinwen Hu,Danyang Wu,Chao Zhu,Ce Hao,Cuncun Xin,Jiangwei Zhang,Jingya Guo,Nannan Li,Guifeng Zhang,Yantao Shi
Emerging heterogeneous catalysts with metal atomically dispersed on supports (tentatively termed single-atom catalysts, SACs) exhibit many appealing features in a wide variety of catalytic reactions , such as high activity and nearly 100% atom utilization. However, the synthesis of SACs currently requires not only multiple procedures but also appropriate precursors with special structures. Herein, the molten-salt assistance is presented as an effective means that enables the use of common metal oxides (such as Fe 2 O 3 and Co 2 O 3 ) and small organic molecules as precursors for the preparation of carbon-supported SACs through one-pot pyrolysis . Molten salts as templates that can be easily removed after synthesis also contribute to the formation of porous and nitrogen-doped carbon with a high specific area. More importantly, benefiting from the strong polarizing force of molten salts, the ionic bonds in oxides can be destabilized at high temperature. Subsequently, metal ions released from solid oxides are transformed into atomically dispersed active sites after being trapped by nitrogen (N) atoms on the carbon support. The as-prepared SAC with atomically dispersed Fe–N 4 sites demonstrates high activity, outstanding stability and good methanol tolerance in the oxygen reduction reaction (ORR) in both alkaline and acidic media.
研究领域:
催化
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材料科学
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化学工程
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产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
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2025
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IF 4.8
Jie Yang,Lixia Ma,Yuqi Zhang,Xuqian Zhao,Shouren Zhang,Luo Huang,Yunpeng Fang,Xiaojie Zhou,Jianghao Kang,Ruibin Jiang
The design of low-cost and highly efficient bifunctional electrocatalyst towards oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is challengeable, which limits the commercial application of rechargeable zinc-air battery. Herein, an efficient ORR and OER bifunctional electrocatalyst (NiFe-LDH/F x −FeN 4 /C) is composed of nickel/iron-based heterostructures sparsely grown on carbon black (CB) with single FeN 4 sites. The NiFe-LDH/F x − FeN 4 /C electrocatalysts are prepared through the pyrolysis of hemin chloride adsorbed on CB, followed by in-situ hydrothermal growth of NiFe-LDH/F x heterostructures. The NiFe-LDH/F x heterostructures are composed of NiFe-LDH, (NH 4 ) 3 FeF 6 , and NiF 2 . The elevated valence states of Fe and Ni in heterostructures significantly increase the OER activity. The mesopores and large pores of the NiFe-LDH/F x − FeN 4 /C facilitate the exposure of active sites and enhance mass transfer. These features contribute to the outstanding bifunctional activity of NiFe-LDH/F x − FeN 4 /C, achieving a half-wave potential of 0.906 V for the ORR, an OER overpotential of 246 mV at 10 mA cm −2 , and an extremely small voltage gap of 0.57 V. Additionally, the NiFe-LDH/F x − FeN 4 /C-based RZAB also exhibits a peak power density of 209 mW cm −2 and charging/discharging cycling stability for 445 h. This work establishes a novel strategy for the preparation of highly efficient bifunctional electrocatalysts through in-situ growth and heterostructure engineering.
研究领域:
电化学
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材料科学
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能量存储与转换
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纳米技术
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催化
✓ 已验证
产品关联
DOI
高影响因子
The Innovation
·
2022
·Vol. 3
·期 4
·100268-100268
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IF 0
Zichuang Li,Ruguang Ma,Qiangjian Ju,Qian Liu,Lijia Liu,Yufang Zhu,Minghui Yang,Jiacheng Wang
Single-site metal atoms (SMAs) on supports are attracting extensive interest as new catalytic systems because of maximized atom utilization and superior performance. However, rational design of configuration-optimized SMAs with high activity from the perspectives of fundamental electron spin is highly challenging. Herein, N-coordinated Fe single atoms are successfully distributed over axial carbon micropores to form dangling-FeN 4 centers (d-FeN 4 ). This unique d-FeN 4 demonstrates much higher intrinsic activity toward oxygen reduction reaction (ORR) in HClO 4 than FeN 4 without micropore underneath and commercial Pt/C. Both theoretical calculation and electronic structure characterization imply that d-FeN 4 endows central Fe with medium spin (t 2g 4 e g 1 ), which provides a spin channel for electron transition compared with FeN 4 with low spin. This leads to the facile formation of the singlet state of oxygen-containing species from triplet oxygen during the ORR, thus showing faster kinetics than FeN 4 . This work provides an in-depth understanding of spin tuning on SMAs for advanced energy catalysis.
研究领域:
催化化学
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材料科学
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理论计算
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DOI
PubMed
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2025
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IF 9.7
Xuebi Rao,Jialin Sun,Liqun Liu,Yongkang Zhu,Shiming Zhang
Regulating the electronic structure of FeN 4 active sites in iron‑nitrogen‑carbon (Fe-N-C) catalysts represents a promising approach to enhance their intrinsic activity for the oxygen reduction reaction (ORR). However, developing effective strategies to achieve heteroatom-doping near FeN 4 sites and gaining mechanistic insights into their ORR electrocatalytic behavior remain significant challenges. In this work, we propose an iodization engineering approach to modulate the charge distribution of FeN 4 centers in a Fe and iodine (I) co-doped N-containing carbon framework (Fe-N-I/CF) catalyst, and investigate the regulatory mechanism of I-doping on the electronic structure of the Fe active sites through spectroscopic characterizations and theoretical calculations. Strategic I-doping at N-rich vacancy defects adjacent to atomic FeN 4 sites with an average Fe I distance of ∼4.2 Å can effectively rebalance the local charge distribution of the Fe center. This rebalancing lowers the free energy barrier of the rate-determining step and induces a continuous downshift of the d-band center, thereby enhancing ORR electrocatalytic performance. The optimized Fe-N-I/CF catalyst exhibits a high half-wave potential of 0.937 V (vs. RHE) and enables zinc-air batteries to achieve a peak power density of 268.8 mW cm −2 with excellent stability over 720 h.
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DOI
PubMed
高影响因子
Journal of Materials Chemistry A
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2023
·Vol. 11
·期 12
·6191-6197
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IF 11.9
Hongzhou Yang,He Huang,Qing Wang,Lu Shang,Tierui Zhang,Shouguo Wang
3d transition metal single atom catalysts (SACs) (e.g. M = Fe, Co, Cu) are considered as promising catalysts for oxygen reduction reaction (ORR), among which Fe SACs display comparable performance to commercial Pt/C. However, Fe SACs still demand significant improvements in activity and stability for further industrial deployment. Herein, a Fe, Cu dual metal SAC was synthesized using a facile ligand-mediated method. Fe and Cu atoms were atomically dispersed on commercial carbon black in the form of FeN4 and CuN4 sites. Owing to the interactions between the adjacent Fe and Cu atoms co-existing in a very tiny area, the as-synthesized Fe, Cu dual metal SAC exhibited excellent ORR performance with a high half-wave potential of 0.926 V and good stability in 0.1 M KOH, which are significantly higher than that of the Fe-SAC or Cu-SAC control samples. Density function theory calculations showed that the Cu single atom can act as an electron donator enriching the electron density of Fe sites, thus endowing the Fe sites with optimized adsorption/desorption energy for ORR intermediates and thereby facilitating the ORR activity of FeCu-SAC. Moreover, a study on three typical commercial carbon substrates indicated that carbon support with high surface areas and hierarchical pore structure was beneficial for ORR. The excellent ORR activity and durability of FeCu-SAC enabled the constructed Zn–air battery to have a high power density of 201.4 mW cm−2 and high specific energy of 827.68 W h kg−1.
研究领域:
材料科学
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催化化学
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能源科学
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产品关联
DOI
高影响因子
CARBON
·
2024
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IF 10.5
Yinghua Wang,Lingmin Wu,Konggang Qu,Xiujun Wang,Baitao Li
The oxygen reduction reaction (ORR) is a crucial step in the energy transformation devices, which requires the fabrication of a cost-effective and energy-efficient Fe single-atom catalyst (SAC) to substitute platinum. However, achieving a controllable synthesis of Fe SAC is a formidable challenge. In this study, a Fe SAC with a novel 3D-on-2D architecture was fabricated by coating 3D metal-organic frameworks (MOFs) over the surface of 2D reduced graphene oxide (rGO). In-situ combining MOF and rGO in a composite structure by adjusting their weight proportion is a key to preparing an active 3D-on-2D structured catalyst with FeN 4 active sites. Thanks to the favorable conductivity of the 2D rGO-derived carbon structure and the 3D MOF structure exposing an enhanced density of FeN 4 sites, FeNC@rGO-2 demonstrates exceptional ORR activity. It performs more effectively than commercial Pt/C, exhibiting excellent half-wave potentials of 0.887, 0.705, and 0.741 V in alkaline, neutral, and acidic solutions respectively. Impressively, FeNC@rGO-2 exhibits excellent stability and methanol tolerance. When FeNC@rGO-2 is assembled as cathode catalyst in Zinc-air batteries (ZAB) and microbial fuel cells (MFC), FeNC@rGO-2-ZAB reveals outstanding power density (393 mW cm −2 ) and good charge/discharge cycling stability. Amazingly, FeNC@rGO-2-MFC also shows superior power density (2810 ± 19 mW m −2 ) and efficiency of electron recovery. This study reveals that FeNC@rGO-2 has extremely high application value in energy conversion devices oriented for alkaline and neutral electrolytes.
研究领域:
材料科学
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电化学
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能源转换
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产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Zhiwen Li,Hezhen Wang,Yan Xie,Yifei Zhang,Jianxin Gao,Yinghao Xu,Li Chen,Liangliang Xu,Erdong Wang,Gao Li
It is of great significance but remains challenging to simultaneously development cost-effective and efficient non-noble metal electrocatalysts (NNMEs) for oxygen reduction reaction (ORR) in both alkaline and acidic solutions. In current work, a multi-component synergism system is developed, which is comprised of molybdenum phosphide (MoP) shell onto iron phosphide clusters anchored on carbon matrixes that embedded with numerous FeN 4 species (MoP/Fe 2 P-FeN 4 ). The optimized MoP/Fe 2 P-FeN 4 electrocatalyst delivers a synergistic enhancement in both alkaline and acidic ORR performances: E 1/2 : 0.885 V (0.1 M KOH electrolyte) and E 1/2 : 0.742 V (0.1 M HClO 4 electrolyte). Furthermore, the equipped zinc-air batteries (ZABs) of MoP/Fe 2 P-FeN 4 exhibit a power density of 140.6 mW cm −2 @219.6 mA cm −2 , which surpasses the corresponding Fe 2 P-FeN 4 and commercial Pt/C catalyst. The computational calculations reveal that MoP/Fe 2 P-FeN 4 shows a relative increase of d -band center closer to Fermin level than Fe 2 P-FeN 4 , tuning the rate-determining step to conversion of *O to *OOH intermediate, thus significant reducing the energy barrier and enhancing ORR activity. This strategy opens new opportunities to rational design of Fe-based nanocomposites for stimulated ORR and further ZAB activities.
研究领域:
材料科学
·
电化学
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催化科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）