Science China-Chemistry
·
2020
·Vol. 63
·期 6
·810-817
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IF 6.356
He Qian,Meng Yuying,Zhang Hao,Zhang Ying,Sun Qingdi,Gan Tao,Xiao Huajian,He Xiaohui,Ji Hongbing
Recently, nitrogen-doped porous carbon supported single atom catalysts (SACs) have become one of the most promising alternatives to precious metal catalysts in oxygen reduction reaction (ORR) due to their outstanding performance, especially those derived from porphyrin-based materials. However, most of them involve other metal residuals, which would cause the tedious pre- and/or post-treatment, even mislead the mechanistic investigations and active-site identification. Herein, we report a precursor-dilution strategy to synthesize Fe SACs through the Schiff-based reaction via co-polycondensation of amino-metalloporphyrin, followed by pyrolysis at high temperature. Systematic characterization results provide the compelling evidence of the dominant presence of atomically dispersed Fe-N x species. Our catalyst shows superior ORR performance with positive half-wave potential ( E 1/2 =0.85 V vs. RHE) in alkaline condition and moderate activity ( E 1/2 =0.68 V vs. RHE) under the acidic condition, excellent methanol tolerance and good long-term stability. All the results indicate Fe SACs would be a promising candidate for replacing the precious Pt in metal-air batteries and fuel cells.
研究领域:
材料科学
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电化学
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催化科学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Zhenyu Yan,Wenyu Gao,Chenkai Zhong,Qiangqiang Jiao,Xiuyun Zhao,Jia Liu
Fe-Nx sites can activate peroxymonosulfate (PMS) in advanced oxidation processes (AOPs) to produce various reactive oxygen species, and have great potential for removing tetracycline (TC), but their formation and catalytic mechanism are rarely studied. Herein, the Fe/N-C catalyst was prepared by crosslinking chitosan (CS) using a coordination complex of Fe 2+ and phenanthroline as the precursor for FeNx. The results of crystal structure, lattice constant, chemical state of N element and structural analysis have demonstrated the successful construction of FeNx sites. The degradation experiments confirmed that the removal efficiency of tetracycline reached up to 90.7 % within 15 min, with a degradation rate of up to 0.184 min −1 . Moreover, the material has exhibited excellent performance in complex water environments and within a broad pH range (pH = 2.30 ∼ 9.88). Mechanism analysis proves that the active substances in the system are 1 O 2 , •O 2 − , SO 4 •− , •OH and Fe IV = O, of which 1 O 2 played the principal role. The FeNx structure is the primary active site, where the redox cycle between Fe 2+ and Fe 3+ , electron transport between pyridinic N, electron-deficient C and PMS produces active components. In addition, based on the various intermediate products detected, two possible TC degradation pathways are reasonably speculated. In this study, the highly active FeNx sites were successfully constructed, and elucidated their activation mechanism towards PMS, which proved the broad prospect of Fe/N-C materials in pollutant degradation.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Ting Yang,Shisuo Fan,Yang Li,Qi Zhou
A high-efficient iron-based heterogeneous catalyst is desired to active peroxymonosulfate (PMS). Due to a large catalytic contribution of atomically dispersed Fe-N x sites, single-atom iron–nitrogen-carbon catalysts exhibit superior performance in the catalytic activation of PMS. Herein, a sequence of Fe-N-C SACs with atomically dispersed Fe-N x sites, Fe SA -N-C and Fe SA -N/C, were prepared from Fe-doped ZIF-8 and FePc@ZIF-8, respectively. Single-atom Fe-N x sites were confirmed to be the main active sites for PMS activation. Fe SA -N/C-20 with a higher density of Fe-N x sites exhibited superior catalytic performance to N/C, Fe SA -N-C, Fe SA -N/C-15, and Fe SA -N/C-25 for BPA degradation. Integrated with chemical quenching experiments, electron spin resonance (ESR), in-situ Raman spectra, and electrochemical analysis, a nonradical pathway was demonstrated to dominate the degradation of BPA in the PMS + Fe SA -N/C-20 system. More importantly, the nature of this nonradical pathway was found to be an electron-transfer regime instead of a high-valent iron or singlet oxygenation process. The BPA was adsorbed onto the Fe-N x site by a “donor–acceptor complex” mechanism to form a nonradical PMS* intermediate during the process. Benefiting from this mechanism, the PMS + Fe SA -N/C-20 system showed wide pH adaptation and high resistance to inorganic anions.
研究领域:
环境科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2023
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IF 6.2
Yunpeng Liu,Xupo Liu,Cuicui Zhang,Ye Chen,Zhitao Wang,Gangya Wei,Jing Zhang,Tianfang Yang,Fengxian Zhang,Shuyan Gao
Fe-N-C catalysts have served as ideal catalysts for oxygen reduction reaction (ORR), but the strong adsorption to ORR-relevant intermediates and less utilization of Fe-N x sites endow those catalysts with inferior performance. Here, an efficient catalyst consisted of Fe-N x species and FeF 2 /Fe 3 C nanoparticles co-anchored on N, F co-doped carbon nanotubes (Fe-NF-CNTs) has been constructed through a surface modification strategy. Sodium trifluoroacetate as functional linker modified on metal-organic framework surface promotes to form abundant and accessible active sites. FeF 2 /Fe 3 C nanoparticles and hydrogen fluoride generated in pyrolysis process facilitate to construct N, F co-doped CNTs with defects and holes. N, F co-doping modifies the adsorption characteristic of Fe-N x sites, while CNTs improve the accessibility of active sites and the capability of material transport. Therefore, Fe-NF-CNTs exhibits outstanding activity (E 1/2 = 0.85 V) and stabilization (ΔE = 6 mV, 10k cycles). Impressively, Fe-NF-CNTs delivers high power density (144 and 68 mW cm –2 ) and cycle stability (300 and 60 h) in liquid and flexible Zn-air batteries, respectively. This work provides a surface modification strategy to guide the tuning of electronic structure of efficient ORR catalysts designed for renewable green energy.
研究领域:
材料科学
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电化学
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
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2025
·
IF 5.1
Xue Zhang,Shihan Kang,Wangxing Cheng,Lei Wang,Nannan Lu,Lin-Wei Chen
Establishing an efficient and sensitive electrochemical sensor for paracetamol (PCM) is of significant importance in pharmaceutical quality control and environmental protection. This paper reports a novel electrochemical sensing platform based on a ZIF-8-derived strategy for fabricating N-doped porous carbon with monodispersed Fe-N x sites (Fe-N/NPC). The introduction of iron phthalocyanine (Fe-Pc) molecules fixed within the ZIF-8 framework prevents the aggregation of metal species during high-temperature treatment, ensuring the high dispersion of Fe-N x sites. Under optimized conditions, Fe-N/NPC-10/GCE electrochemical sensor exhibits excellent performance for PCM detection, which is mainly attributed to the synergistic enhancement between Fe-N x and NPC. The high surface area of NPC with a porous structure and N doping effect, which enhances its adsorption capacity for PCM, facilitating electron transfer and thereby amplifying the response signal. At the same time, the high-density monodispersed Fe-N x provides abundant catalytic active sites, improving electrocatalytic activity. Through the investigation of how buffer solution pH affects the oxidation peak induced by PCM, a pH of 7.0 was ultimately determined to be the optimal value. Using differential pulse voltammetry (DPV), the Fe-N/NPC-10/GCE electrochemical sensor demonstrates a wide detection range (0.1–10, 10–150 μM) for PCM with a detection limit (LOD) of 0.019 μM. Furthermore, the sensor exhibits good selectivity, stability, and reproducibility, and has been successfully applied for the determination of PCM in real pharmaceutical samples, with a recovery rate close to 100 %, indicating that the analytical method performs well and is suitable for analysis of real samples.
研究领域:
材料科学
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分析化学
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药物分析
✓ 已验证
产品关联
DOI
高影响因子
RUSSIAN JOURNAL OF GENERAL CHEMISTRY
·
2025
·Vol. 95
·期 6
·1455-1463
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IF 0.8
Chen X.,Xiu X.,Zhuang X.,Sun H.,Dong C.
Developing cost-effective and efficient non-precious metal oxygen reduction catalysts (ORRs) is crucial for advancing renewable energy technologies. This study reports the synthesis and characterization of a novel non-precious metal catalyst, N–C–Fe-600, synthesized via a simple two-step method. Pyrolysis of NH 2 –MIL-88(Fe) under an inert atmosphere, followed by acidic treatment, yielded a porous N–C–Fe-600 material featuring a high surface area and a substantial concentration of active Fe–N x sites. Electrochemical characterization revealed that N–C–Fe-600 exhibits ORR activity comparable to commercial Pt/C catalysts, along with significantly enhanced stability and methanol tolerance. The catalyst demonstrates a near-ideal four-electron transfer pathway, suggesting its potential as a viable alternative to platinum-based catalysts in fuel cells.
研究领域:
材料科学
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电化学
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催化
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纳米技术
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能源技术
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2023
·
IF 13.1
Katam Srinivas,Zhuo Chen,Anran Chen,Fei Ma,Ming-qiang Zhu,Yuanfu Chen
The development of efficient single-atom catalysts (SACs) for the oxygen reduction reaction (ORR) remains a formidable challenge, primarily due to the symmetric charge distribution of metal single-atom sites (M-N 4 ). To address such issue, herein, Fe-N x sites coupled synergistic catalysts fabrication strategy is presented to break the uniform electronic distribution, thus enhancing the intrinsic catalytic activity. Precisely, atomically dispersed Fe-N x sites supported on N/S-doped mesoporous carbon (NSC) coupled with FeS@C core-shell nanoparticles (FAS-NSC@950) is synthesized by a facile hydrothermal reaction and subsequent pyrolysis. Due to the presence of an in situ-grown conductive graphitic layer (shell), the FeS nanoparticles (core) effectively adjust the electronic structure of single-atom Fe sites and facilitate the ORR kinetics via short/long-range coupling interactions. Consequently, FAS-NSC@950 displays a more positive half-wave potential ( E 1/2 ) of 0.871 V with a significantly boosted ORR kinetics (Tafel slope = 52.2 mV dec −1 ), outpacing the commercial Pt/C ( E 1/2 = 0.84 V and Tafel slope = 54.6 mV dec −1 ). As a bifunctional electrocatalyst, it displays a smaller bifunctional activity parameter (Δ E ) of 0.673 V, surpassing the Pt/C-RuO 2 combination (Δ E = 0.724 V). Besides, the FAS-NSC@950-based zinc-air battery (ZAB) displays superior power density, specific capacity, and long-term cycling performance to the Pt/C-Ir/C-based ZAB. This work significantly contributes to the field by offering a promising strategy to enhance the catalytic activity of SACs for ORR, with potential implications for energy conversion and storage technologies.
研究领域:
电化学
·
材料科学
·
能量转换与存储
✓ 已验证
产品关联
DOI
高影响因子
Green Energy & Environment
·
2020
·
IF 6.395
Hongtai Li,Yanxiao Chen,Quan Jin,Wei Xiang,Benhe Zhong,Xiaodong Guo,Bao Wang
Serious shuttle effect and sluggish conversion kinetics of lithium polysulfides (LiPSs) have a massive impact on obstructing the practical application of lithium-sulfur (Li–S) batteries. To address such issues, Fe-Nx sites enriched microporous nanoflowers planted with tangled bamboo-like carbon nanotubes (Fe-Nx-C/Fe 3 C-CNTs NFs) are found to be effective catalytic mediators with strong anchoring capabilities for LiPSs. The bamboo-like carbon nanotubes catalyzed by Fe 3 C/Fe entangled each other to form a conductive network, which encloses a flower-like microporous carbon core with embedded well-dispersed Fe-Nx active sites. As expected, electrons smoothly transfer along the dense conductive bamboo-like carbon network while the flower-like carbon core consisting of micropores induces the homogeneous distribution of tiny sulfur and favors the lithium ions migration with all directions. Meanwhile, Fe-Nx sites strongly trap long-chain LiPSs with chemical anchoring, and catalyze the redox conversion of LiPSs. Due to the aforementioned synergistic effects, the [email protected] /Fe 3 C-CNTs NFs cathode exhibited a remarkable specific capacity (635 mAh g s −1 ) at 3 C and a favorable capacity decay with 0.04% per cycle even after 400 cycles at 1 C.
研究领域:
材料科学
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能源存储
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电化学
·
纳米技术
✓ 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）