ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Yinling Wang,Juan Wang,Dandan Wei,Maoguo Li
M–N–C electrocatalysts for the oxygen reduction reaction (ORR) have been considered as the most promising alternatives to precious metal catalysts. However, the catalytic activity of M–N–C especially in an acidic medium is still unable to meet the practical requirement, and the corresponding ORR mechanism also remains unclear. Herein, an “MOF-protective-pyrolysis” strategy was adopted to synthesize an Fe–N–C catalyst (P-FeMOF@ZIF-8) with Fe–N4 as the predominant Fe species. The P-FeMOF@ZIF-8 displays high catalytic activity in both acidic and alkaline mediums. The experimental results further reveal the different importance of the Fe species in different mediums. Based on the results, a distinct mechanism of the ORR the in acidic medium was proposed, where the synergistic effect of the Fe–N4 site and carbon in improving the kinetics of the ORR were well explained. The findings and the corresponding perspective may provide a new guidance for the design of highly efficient ORR electrocatalysts.
研究领域:
材料科学
·
电化学
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DOI
PubMed
高影响因子
CHINESE CHEMICAL LETTERS
·
2021
·
IF 6.779
Min Zhang,Bolong Yang,Ting Yang,Yahui Yang,Zhonghua Xiang
Unremitting and intensive researches about efficient non-precious metal electrocatalysts are necessary for large-scale commercial applications of fuel cells, while iron and nitrogen co-doped carbon (Fe-N-C) materials has become one of the most promising electrocatalysts to replace Pt-based noble metal catalysts . However, the traditional Fe-doped ZIF with rhomb dodecahedron morphology limits the exposure of active sites and the utilization of atoms, even affecting the performance of the catalyst. Herein, a Fe/N co-doped catalyst with a flower-like morphology was prepared using ferric citrate source along with secondary NH 3 heat treatment. The optimal catalyst (termed as 4Fe citrate -N-C-3) showed distinguished oxygen reduction reaction (ORR) activity with a half-wave potential of 0.8 and 0.9 V ( vs . RHE) in acid and alkaline media, respectively. In addition, 4Fe citrate -N-C-3 maintained more than 80% of original activity even after 50,000 s which is superior to the benchmark Pt/C. The strategy of controlling morphology and composition is meaningful for the optimization of non-precious metal electrocatalysts for ORR in fuel cells or metal-air batteries .
研究领域:
材料科学
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电化学
·
能源存储与转换
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产品关联
DOI
高影响因子
TRANSACTIONS OF TIANJIN UNIVERSITY
·
2024
·
IF 6.7
Liu Weihao,Liu Qingtao,Wan Xin,Shui Jianglan
Non-precious metal electrocatalysts (such as Fe–N–C materials) for the oxygen (O 2 ) reduction reaction demand a high catalyst loading in fuel cell devices to achieve workable performance. However, the extremely low solubility of O 2 in water creates severe mass transport resistance in the thick catalyst layer of Fe–N–C catalysts. Here, we introduce silicalite-1 nanocrystals with hydrophobic cavities as sustainable O 2 reservoirs to overcome the mass transport issue of Fe–N–C catalysts. The extra O 2 supply to the adjacent catalysts significantly alleviated the negative effects of the severe mass transport resistance. The hybrid catalyst (Fe–N–C@silicalite-1) achieved a higher limiting current density than Fe–N–C in the half-cell test. In the H 2 –O 2 and H 2 –air proton exchange membrane fuel cells, Fe–N–C@silicalite-1 exhibited a 16.3% and 20.2% increase in peak power density compared with Fe–N–C, respectively. The O 2 -concentrating additive provides an effective approach for improving the mass transport imposed by the low solubility of O 2 in water.
研究领域:
材料科学
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电化学
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能源工程
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产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2022
·
IF 8.129
Qin Wen,Dongxu Tian,Zequan Zeng,Fei Qi,Zhanggen Huang
Fe-N-C catalysts with magnetism were successfully synthesized through one-step heat treatment of ferrosoferric oxide and covalent organic frameworks composite (Fe 3 O 4 @COF) as heterogeneous catalysts for persulfate (PS) activation and 2,4-dichlorophenol (2,4-DCP) degradation. The morphologies, compositions and active sites were adjusted by changing the pyrolysis temperature. The catalyst prepared at 900 °C showed excellent activity with 2,4-DCP removal of 90% in 60 min, recycling convenience and regeneration stability. Large surface area (342 m 2 g −1 ) and hierarchical porous structure benefited PS activation. It was proved that the radical and non-radical mechanisms coexisted in Fe-N-C-900/PS system with the results of quenching and electrochemical experiments. Roles of graphitic N and Fe-N X were distinguished. Graphitic N and Fe-N X sites palyed an prominent part in the non-radical activation process , in which Fe-N X was closely related to the electron transfer activation mechanism. Density functional theory (DFT) calculation further verified that the Fe N 2 was the key site for PS activation. 2,4-DCP degradation was proved to be a toxicity-attenuation process according to the biotoxicity analysis. The effects of several operating parameters and degradation of different model pollutants were also systematically evaluated, and possible activation mechanism was proposed.
研究领域:
环境科学
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催化化学
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2023
·
IF 13.6
Wen Song,Xinyu Xiao,Guanlong Wang,Xiaoli Dong,Xiufang Zhang
Supporting Fe catalysts on N doped carbon (Fe-N-C) renders a promising way towards peroxymonosulfate (PMS) activation for water decontamination , but constructing high-efficiency Fe-N-C remains challenging due to the insufficient understanding of the structure-performance relationship. Herein, the N doped carbon nanotube supported Fe catalysts (Fe-NCNT) were prepared towards PMS activation for organic pollutants removal, in which the Fe-N coordination number and Fe species were tuned through changing the pyrolysis temperature to study their roles in PMS activation. Results showed increasing the pyrolysis temperature converted the Fe-N 4 structure in Fe-NCNT to low-coordinated Fe-N 3 structure and produced Fe nanoparticles (FeNP, encapsulated in carbon). The Fe-NCNT with Fe-N 3 and FeNP exhibited a remarkably high specific activity (0.119 L min −1 m −2 ), which was 1.8 times higher than that of Fe-NCNT with only Fe-N 4 and obviously outperformed those of the state-of-the-art PMS activators. The low-coordinated structure and FeNP promoted the PMS reduction on Fe 2+ of Fe-N x for •OH and SO 4 •− production, which served as major oxidants for pollutants degradation . The experimental results and theoretical calculation corroborated the low-coordinated structure and FeNP jointly enhanced the PMS adsorption and electron density on Fe center, which accelerated electron transfer from Fe center to PMS for radical production.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
CATALYSIS LETTERS
·
2023
·Vol. 153
·期 12
·3569-3580
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IF 2.8
Lin Shanshan,Liu Jianguo,Ma Longlong
Aniline is a group of important platform molecules that has been widely used in the synthesis of other high-value chemicals and pharmaceutical products. How to produce high-value anilines as the high-value chemical intermediates more efficiently and environmentally has always been a research topic in the industry. Catalytic hydrogenation is an environmentally friendly method for preparing halogenated anilines. Traditional noble metal catalysts face the problems of cost and noble metals residue. To improve the purity of the product as well as the activity and recyclability of the catalyst, we prepared a Pd/Fe magnetic bimetallic catalyst supported on N-doped carbon materials to reduce nitrobenzene to aniline under mild conditions. The catalyst has a low Pd loading of 2.35%. And the prepared bimetallic Pd/Fe@N/C catalyst showed excellent catalytic reactivity with the nitrobenzene conversion rate of 99%, and the aniline selectivity of 99% under mild reaction conditions of 0.8 MPa H 2 and 40 °C. A variety of halogenated and aliphatic nitro compounds were well tolerated and had been transformed to the corresponding target amine products with excellent selectivity. In addition, the novel N-doped graphene-encapsulated bimetallic magnetic Pd/Fe@N/C catalyst not only had magnetic physical properties, which was easy to separate, recover, and used for the recycling of the catalyst without metal leaching but also catalyzed highly selective reductive amination of aromatics was a green, economical and environmentally friendly reaction with the only by-product of H 2 O. Graphical Abstract
研究领域:
化学
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催化
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材料科学
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环境科学
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产品关联
DOI
PubMed
高影响因子
CARBON
·
2020
·
IF 8.821
Shuqi Hu,Wenpeng Ni,Daihui Yang,Chao Ma,Jiaheng Zhang,Junfei Duan,Yang Gao,Shiguo Zhang
Atomically dispersed Fe–N–C catalysts with additional Fe-containing nanoparticles including metal, carbides or oxides have shown great potentials towards oxygen reduction reaction (ORR) catalysis. However, the formation of these synergistically active nanoparticles and the effect of the porous carbon structures remain unclear. In this work, a novel single-atom-involved electrochemical catalyst, i.e. , Fe 3 O 4 nanoparticles encapsulated in atomically dispersed Fe–N–C (Fe 3 O 4 @FeNC) was reported. The optimized Fe 3 O 4 @FeNC exhibits excellent ORR activity with a half-wave potential of 0.890 V and a Tafel slope of 58.8 mV dec −1 , comparable with recently reported ORR catalysts and superior to these of commercial Pt/C. More importantly, the porous architectures not only affect the mass transfer and active sites, but casts huge influence on the nucleation of Fe 3 O 4 nanoparticles, the graphitization degree of the carbon support, the chemical environments of the elements, and the ORR catalytic pathways. Density functional theory calculations show stronger O 2 adsorption on Fe–N–C when supported on Fe 3 O 4 moieties, which may increase the reactant concentration for ORR and promote the overall activity. These findings will provide important references for the future understanding and design of single-atom-involved catalysts with enhanced electrochemical properties .
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
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2018
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IF 8.097
Fei He,Li Mi,Yanfei Shen,Toshiyuki Mori,Songqin Liu,Yuanjian Zhang
Developing highly efficient biomimetic catalysts that directly use O2 as the terminal oxidant to dehydrogenate and monoxygenate substrates with high selectivity under mild conditions has long been pursued but rarely achieved yet. Herein, we report that heterogeneous Fe–N–C, which is commonly used as an electrocatalyst for oxygen reduction reaction, had unusual biomimetic catalytic activity in both dehydrogenation and monoxygenation of a series of organic molecules (∼100% selectivity) by directly using O2. The Fe–Nx center was verified to be the active site that reductively activated O2 by spontaneously generating specific reactive oxygen species (ROS) (1O2, O2•–, and H2O2). Aided by these ROS, under physiological conditions, the Fe–N–C was further successfully exampled to kill proliferative lung cancer cells. Fe–N–C had several striking superior features with respect to natural enzymes, classical heterogeneous nanozymes, and homogeneous artificial enzymes incapable of working under harsh conditions (extreme pH and high temperature), ease of separation and recycling, and direct use of O2. It would open up a new vista of Fe–N–C as an artificial enzyme in biomimetic catalysis, ranging from fundamental simulation of oxidase/oxygenase metabolism to industrial oxidation processes and to disease treatment.
研究领域:
催化
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生物化学
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材料科学
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肿瘤学
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酶学
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 16
·9543-9549
·
IF 4.036
Tanlun Wang,Chenxiang Sun,Yong Yan,Fan Li
Metal–N–C-based catalysts prepared by pyrolysis are frequently used in the oxygen reduction reaction (ORR). Zeolitic imidazolate frameworks (ZIFs), a type of metal organic framework (MOF), are selected as precursors due to their special structure and proper pore sizes. A series of Fe–N–C catalysts with different concentrations of 2-methylimidazole were prepared with a simple solvothermal-pyrolysis method, and the transformation productivity, morphology and ORR activity were investigated. It was found that the Fe–N–C catalyst with a 2-methylimidazole concentration of 0.53 mol L−1 had the best performance. In 0.1 M KOH solution, the half-wave potential was 0.852 V (vs. RHE), with the highest electrochemically active surface area (ECSA) of 94.1 cm2, and the ORR reaction was dominated by a 4-electron process. The current only decreased by 10.5% after 50 000 s of chronoamperometry (CA), while the half-wave potential only decreased 20 mV in 3 M methanol. Additionally, this catalyst cannot be poisoned by Cl− and SO32− ions in the ORR process. Finally, some typical ions including SCN−, Fe(CN)63− and Fe(CN)64− were used to inhibit the active sites, and it was determined that Fe(II) is the real active species. The series of synthesis and testing experiments has significance in guiding optimization of the synthesis conditions and analysis of the mechanism of active sites in Fe–N–C materials.
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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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
·
IF 4.939
Wenyu He,Jinhui Wei,Ting Huang,Enren Zhang
For practical applications of microbial fuel cells (MFCs), 5H-dibenz [b,f] azepine-5-carboxamide (Carbamazepine, CBZ) was used as the organic precursor for the synthesis of catalysts composed of Fe–N–C complexes (named as Fe-CBZ-Cats) through a sacrificial support method. Characterizations by SEM, XPS and TEM-EDS elemental mapping show that the synthesized Fe-CBZ-Cats have porous structure and uniformly dispersed Fe/N/C complex centers which could play key roles in effective ORR . Linear scanning voltammetry (LSV) measurements show that the synthesized Fe-CBZ-Cats exhibits ORR activity comparable to commercial Pt/C catalysts under the same catalyst loading (2 mg cm −2 ). The maximum power density produced by cathode-limiting MFCs with Fe-CBZ-Cats air cathodes was 431 ± 23 μW cm −2 , higher than those in the control MFCs with Pt/C air cathodes (403 ± 13 μW cm −2 ) and activated carbon air cathodes (296 ± 24 μW cm −2 ). In addition, the toxicity tolerance of the synthesized Fe-CBZ-Cats is much higher than Pt/C.
研究领域:
环境科学
·
电化学
·
生物工程
✓ 已验证
DOI
高影响因子
Catalysts
·
2025
·Vol. 15
·期 9
·850
·
IF 4
Qiongqiong He,Xuewen Wu,Ping Ma,Zhaoyang Song,Xiaoqi Wu,Ruize Gao,Zhenyong Miao
Phenol is a refractory organic pollutant that is difficult to degrade in wastewater treatment, and efficiently and stably degrading phenol presents a significant challenge. In this study, iron-doped humic acid-based nitrogen–carbon materials were prepared to activate peroxymonosulfate (PMS) for the degradation of phenol. The Fe-N-C/PMS system achieved a phenol degradation rate of 99.71%, which follows a first-order kinetic model, with the reaction rate constant of 0.1419 min−1. The phenol degradation rate remained above 92% in inorganic anions (Cl−, SO42−, HCO3−) and humic acid and the system maintained a 100% phenol removal rate over a wide pH range (3–9). The iron in the catalyst predominantly exists in the forms of Fe0and Fe3C, and Fe0, Fe2+/Fe3+are the main active sites that promote PMS activation during the reaction. Additionally, Fe-N-C has a large specific surface area (1041.36 m2/g). Quenching experiments and electron spin resonance (ESR) spectroscopy detected the active free radicals in the Fe-N-C/PMS system: SO4•−, •OH, O2•−, and1O2. The mechanism for phenol degradation was discussed, involving radical pathways (SO4•−, •OH, O2•−) and the non-radical pathway (1O2), in the Fe-N-C/PMS system activated by Fe0, Fe2+/Fe3+, sp2hybridized carbon, C-O/C-N, C=O, and graphitic nitrogen active sites. This study provides new insights into the synthesis of efficient carbon-based catalysts for phenol degradation and water remediation.
研究领域:
环境科学
·
材料化学
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水体修复
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催化
·
污染物降解
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产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Xilong Wang,Qinghua Zhang,Hechun Jiang,Yadong Li,Hongwei Zhu,Lirong Zheng,Lin Gu,Han-Pu Liang
Pt-based intermetallic alloys with high activity and stability are promising for accelerating the cathodic oxygen reduction reaction (ORR) and large-scale application of proton exchange membrane fuel cells. So far, facile synthesis of Pt-based alloys in less time is desirable but still challenging. Herein, based on the traditional wet impregnation method, facile in situ reduction of H2PtCl6 and alloying with a hybrid nanostructure mainly doped with Fe single atoms as well as small amounts of Fe-based nanoparticles and oxides were developed to fabricate highly dispersed PtFe nanoparticles loaded on a mesoporous Fe–N–C support. Alloying of Pt derived from H2PtCl6 with various iron-based species existing in forms of single-atom, metallic, and oxide states was confirmed by systematic characterization, and the Fe content in the support is important for PtFe alloy formation, and the corresponding electrochemical performance promotion has been identified. The as-synthesized best-performance PtFe/Meso-PDA-5 catalyst delivered a high potential of 0.925 V at a current density of 3 mA cm–2 and achieved a high mass activity of 497.5 mA mgPt–1 at 0.9 V for the ORR in 0.1 M HClO4. More importantly, only 17.9% mass activity loss was observed after 10k potential cycles of the accelerated deterioration test. The present work provides a strategy for facile synthesis of Pt-based alloy nanomaterials for ORR catalysis and highlights the importance of supports in alloy formation.
研究领域:
材料科学
·
电化学
·
催化
·
能源材料
✓ 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）