Nano-Micro Letters
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2019
·Vol. 11
·期 1
·1-17
·
IF 9.043
Niu Qijian,Chen Binling,Guo Junxia,Nie Jun,Guo Xindong,Ma Guiping
Developing an efficient and durable oxygen reduction electrocatalyst is critical for clean-energy technology, such as fuel cells and metal–air batteries. In this study, we developed a facile strategy for the preparation of flexible, porous, and well-dispersed metal–heteroatom-doped carbon nanofibers by direct carbonization of electrospun Zn/Co-ZIFs/PAN nanofibers (Zn/Co-ZIFs/PAN). The obtained Zn/Co and N co-doped porous carbon nanofibers carbonized at 800 °C (Zn/Co–N@PCNFs-800) presented a good flexibility, a continuous porous structure, and a superior oxygen reduction reaction (ORR) catalytic activity to that of commercial 20 wt% Pt/C, in terms of its onset potential (0.98 V vs. RHE), half-wave potential (0.89 V vs. RHE), and limiting current density (− 5.26 mA cm −2 ). In addition, we tested the suitability and durability of Zn/Co–N@PCNFs-800 as the oxygen cathode for a rechargeable Zn–air battery. The prepared Zn–air batteries exhibited a higher power density (83.5 mW cm −2 ), a higher specific capacity (640.3 mAh g −1 ), an excellent reversibility, and a better cycling life than the commercial 20 wt% Pt/C + RuO 2 catalysts. This design strategy of flexible porous non-precious metal-doped ORR electrocatalysts obtained from electrospun ZIFs/polymer nanofibers could be extended to fabricate other novel, stable, and easy-to-use multi-functional electrocatalysts for clean-energy technology.
研究领域:
材料科学
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能源技术
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DOI
PubMed
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2022
·
IF 4.598
Tao Wang,Jing Feng,Qian Liu,Xiaofeng Han,Dongling Wu
Here, a simple and green synthesis process of Fe/N-codoped reduced graphene oxide (Fe-N-C/NG) with high electrocatalytic activity for oxygen reduction reaction (ORR) is reported. The synthesis of 3D porous structure of Fe-N-C/NG composites involves thermal drying the mixture of graphene oxide (GO), iron nitrate and aspartic acid (Asp) directly, follow by pyrolysis the mixture. The Asp is introduced as an environment-friendly nitrogen and carbon source, and the iron nitrate serves as the pore-forming agent and a gas producer that prevents the agglomeration of graphene. The as-prepared Fe-N-C/NG exhibits 3D loose porous structure with larger specific surface area (245 m 2 g - 1 ). The Fe-NC/NG composite exhibits the onset potential of 0.91 V, a half-wave potential (E 1/2 = 0.83 V), low Tafel slope and four-electron selectivity (n = 3.99) in alkaline solution. Furthermore, the stability test manifests the outstanding stability of Fe-NC/NG electrocatalyst and a superior methanol tolerance than Pt/C electrodes. Particularly, when the prepared Fe-NC/NG-3 catalyst is used as an air electrode catalyst in an assembled Zn-air battery, it exhibits a high specific capacity of 848.2 mAh g Zn -1 and displays more stability than Pt/C. This work provides an effective strategy for preparing high ORR and Zn-air battery performance Fe/N-codoped reduced graphene oxide materials.
研究领域:
材料科学
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电化学
·
能源科学
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DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2023
·
IF 22.1
Yuan Li,Miao-Ying Chen,Bang-An Lu,Hao-Ran Wu,Jia-Nan Zhang
Although the Mn-N-C catalyst has low toxicity and high durability, its intense pH-dependent ORR activity is perplexing and prevents its commercial use in PEMFCs. Herein, we have developed a novel understanding of the role of hydrogen peroxide in the pH-dependent activity and stability of Mn-N-C catalysts. Instead of nitrogen protonation, the strong pH effects of ORR activity are caused by the much faster kinetics of the H 2 O 2 reduction reaction in alkaline medium than in acid, due to the lower dissociation energy of the HO-OH bond in alkaline environment. Regarding durability, the deactivation induced by H 2 O 2 demonstrates a strong pH dependence, primarily due to the differing intensities of reactive oxygen species at different pH values. Correspondingly, isopropanol effectively reduces Fenton reagents and increases the acid resistance of Mn-N-C sites. The present research provides a mechanistic understanding of pH effects and paves the way for the creation of more efficient catalysts.
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高影响因子
ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Junli Nie,Mei Dong,Guangkai Chen,Nannan Wang,Jun Nie,Guiping Ma
Although the Zn-air battery has many advantages, its short practical life hinders its development. Many solutions have been proposed and extensively studied. In this paper, a cobalt-nitrogen co-doped hierarchical porous carbon-based bifunctional catalyst (Co/N-HPCs-800) is reported, using sustainable and low-cost sodium alginate (Na-Alg), a common seaweed extract, as a precursor to complex excess metal particles. The hydrogel network formed by the exchange of sodium ions with metal cation (Co2+) ions is the key to the controllable synthesis of highly dispersed metal atoms. Co/N-HPCs-800 shows excellent catalytic performance and durability in oxygen reduction reaction (E1/2 = 0.86 V) and oxygen evolution reaction (367 mV @ 10 mA cm–2). Importantly, we only attenuated the half-wave potential by 8 mV after more than 50,000 cycles. In addition, the Zn-air batteries (ZABs) using Co/N-HPCs-800 as a cathode exhibit a power density up to 159.67 mW cm–2 and a high specific capacity of 787.94 mA h g–1. This work opens up practical new strategies for synthesizing excess metal catalysts in low cost, effectively improving the service life of Zn-air batteries.
研究领域:
材料科学
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能源化学
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催化化学
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DOI
高影响因子
ACS Catalysis
·
2022
·
IF 13.7
Yuting He,Xiaoxuan Yang,Yunsong Li,Liting Liu,Shengwu Guo,Chengyong Shu,Feng Liu,Yongning Liu,Qiang Tan,Gang Wu
Single-metal site catalysts have exhibited highly efficient electrocatalytic properties due to their unique coordination environments and adjustable local structures for reactant adsorption and electron transfer. They have been widely studied for many electrochemical reactions, including oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). However, it remains a significant challenge to realize high-efficiency bifunctional catalysis (ORR/OER) with single-metal-type active sites. Herein, we report atomically dispersed Fe–Co dual metal sites (FeCo–NC) derived from Fe and Co co-doped zeolitic imidazolate frameworks (ZIF-8s), aiming to build up multiple active sites for bifunctional ORR/OER catalysts. The atomically dispersed FeCo–NC catalyst shows excellent bifunctional catalytic activity in alkaline media for the ORR (E1/2 = 0.877 V) and the OER (Ej=10 = 1.579 V). Moreover, its outstanding stability during the ORR and the OER is comparable to noble-metal catalysts (Pt/C and RuO2). The atomic dispersion state, coordination structure, and the charge density difference of the dual metal site FeCo–NC were characterized and determined using advanced physical characterization and density functional theory (DFT) calculations. The FeCo–N6 moieties are likely the main active sites simultaneously for the ORR and the OER with improved performance relative to the traditional single Fe and Co site catalysts. We further incorporated the FeCo–NC catalyst into an air electrode for fabricating rechargeable and flexible Zn–air batteries, generating a superior power density (372 mW cm–2) and long-cycle (over 190 h) stability. This work would provide a method to design and synthesize atomically dispersed multi-metal site catalysts for advanced electrocatalysis.
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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DOI
高影响因子
Journal of Energy Chemistry
·
2024
·
IF 14
Yugang Qi,Qing Liang,Kexin Song,Xinyan Zhou,Meiqi Liu,Wenwen Li,Fuxi Liu,Zhou Jiang,Xu Zou,Zhongjun Chen,Wei Zhang,Weitao Zheng
Atom-level modulation of the coordination environment for single-atom catalysts (SACs) is considered as an effective strategy for elevating the catalytic performance. For the MN x site, breaking the symmetrical geometry and charge distribution by introducing relatively weak electronegative atoms into the first/second shell is an efficient way, but it remains challenging for elucidating the underlying mechanism of interaction. Herein, a practical strategy was reported to rationally design single cobalt atoms coordinated with both phosphorus and nitrogen atoms in a hierarchically porous carbon derived from metal-organic frameworks. X-ray absorption spectrum reveals that atomically dispersed Co sites are coordinated with four N atoms in the first shell and varying numbers of P atoms in the second shell (denoted as Co-N/P-C). The prepared catalyst exhibits excellent oxygen reduction reaction (ORR) activity as well as zinc-air battery performance. The introduction of P atoms in the Co-SACs weakens the interaction between Co and N, significantly promoting the adsorption process of *OOH, resulting in the acceleration of reaction kinetics and reduction of thermodynamic barrier, responsible for the increased intrinsic activity. Our discovery provides insights into an ultimate design of single-atom catalysts with adjustable electrocatalytic activities for efficient electrochemical energy conversion.
研究领域:
材料科学
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电化学
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催化科学
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产品关联
DOI
高影响因子
Materials Science and Engineering B-Advanced Functional Solid-State Materials
·
2025
·
IF 4.6
Nazhen Zhang,Lijuan Ma,Jing Zang,Yue Gao,Yue Zhong,Songyang Sun,Yanwei Li,Yanhui Li
The exquisitely engineered multifunctional electrocatalysts for oxygen reduction reactions (ORR), hydrogen evolution reactions (HER) and oxygen evolution reactions (OER) hold significant importance in current research. In this work, layered porous C-FeNC-900 electrocatalyst has been successfully prepared using a NaCl induced pyrolysis strategy based on metal organic frameworks (MOFs). The presence of NaCl during the pyrolysis process not only effectively enhances the porous structures, but also promotes numerous Fe N x active sites and improves the degree of carbon graphitization. Due to the simultaneous construction of highly active Fe N x sites on the graded porous carbon skeleton, the electrochemical accessibility and corrosion resistance are improved. The prepared C-FeNC-900 electrocatalyst exhibits a half wave potential of 0.859 V for ORR in alkaline conditions, exceeds the half wave potential of Pt/C at 0.854 V. Moreover, the results demonstrate C-FeNC-900 has excellent stability, with an initial current density retention of 88.45 % after a durability lasting 10,000 s. At the same time, C FeNC-900 has possesses a potential of 1.67 V at a current density of 10 mA cm −2 during OER testing, with a Tafel slope of 209 mV. The C FeNC-900 also displays HER performance with potential of 405 mV and Tafel slope of 178.4 mV. This study provides a new perspective to construct multifunctional catalysts with well-designed structure for clean energy conversion technologies.
研究领域:
材料化学
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电化学
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纳米催化
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能源材料
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多孔材料科学
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可持续能源技术
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产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2021
·Vol. 168
·期 1
·016504
·
IF 4.316
Haomin Jiang,Yujuan Cheng,Zhaohui Wang,Zhiqun Bai,Yang Tang,Yanzhi Sun,Pingyu Wan,Yongmei Chen
The cleavage of the linkage bonds among the C9 units in lignin molecules via selective oxidation method to obtain small-weight aromatic compounds is an important way to lignin valorisation. In this study, the cleavage pathways of bonds in a lignin model compound, GGE (guaiacylglycerol-β-guaiacyl ether), by the reactive oxygen species (ROS) in situ generated through electrochemical oxygen reduction reaction (ORR) in an aprotic ionic liquid ([BMIM]BF4) was investigated. The results indicated that when the main ROS was ·OOH, coniferyl alcohol, guaiacol and vanillin were detected as the degradation products which is supposed to be caused by β-O-4 bonds cleavage; Otherwise, when HO2− was the main ROS, coniferyl alcohol could not be detected and the degradation reaction is believed to be trigerred by Cα-Cβ bonds cleavage.
研究领域:
生物化学
·
环境科学
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DOI
高影响因子
CARBON
·
2024
·
IF 10.5
Yongqing Shen,Peizhi Liu,Yangrui Li,Jianghong Wu,Yanhui Song,Junjie Guo
The structural stability of supported metal nanoparticles determines the activity and longevity of heterogeneous catalysts. Unfortunately, the chemical/thermal working environment inevitably accelerates metal sintering to larger crystallites that leads to the degradation of catalytic performance. Here, we demonstrate that the distribution of defects in carbon support as an inherent parameter plays a crucial role in catalyst sintering. Based on in-situ transmission electron microscopy studies, the strong metal-support interaction between platinum (Pt) nanoparticles and defect-rich graphene nanoflakes largely suppresses metal sintering up to 700 °C. Particularly, the optimal carbon support can be achieved in the annealing process, in which the mass transfer and charge transport can be enhanced by accurately manipulating the distribution of defects in carbon matrix and graphitization degree. It is worth noting that the screened Pt/GNs-300 exhibits impressive oxygen reduction reaction performance with high half-wave potential (0.91 V), mass activity (108.1 A g –1 Pt ) and excellent stability. By its ascendancy in ORR, the Pt/GNs-300 exhibits a high open-circuit voltage of 1.41 V and a maximum power density of 198.6 mW cm −2 in Zn-air battery, implying its brilliant practicability. This work paves a pathway for achieving sinter-resistant metal-loaded catalysts in energy electrocatalysis.
研究领域:
材料科学
·
电催化
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产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2026
·
IF 9.6
Chao Huang,Yingnan Dou,Liping Sun,Lihua Huo,Qiang Li,Hui Zhao
The mechanism by which the multicomponent systems in high-entropy perovskites regulate catalytic sites remains unclear, especially how the introduction of A-site elements with different radii influences the B-site catalytic centers. This study designed medium-entropy perovskite oxides, (La 0.2 Pr 0.2 Nd 0.2 Sm 0.2 M 0.2 ) 2 NiO 4 (M = Ca, Sr, Ba), by leveraging the differential ionic potentials of strategically selected alkaline earth metals, with the aim of elucidating how systematic modifications of the local polar environment influence the bonding state of catalytic sites and their electrocatalytic behavior. The differing ionic potentials of the A-site cations (Ca, Sr, Ba) modulate the bond strength and electron cloud overlap of the B-site transition metal‑oxygen bonds. This modulation, primarily through coulombic interactions with the B-site metal ions, induces significant electron transfer and consequently adjusts the energy of the d-band center. This weakened interaction facilitates the generation and migration of active oxygen species by lowering the metal‑oxygen bond strength. Electrochemical results indicate that (La 0.2 Pr 0.2 Nd 0.2 Sm 0.2 Ba 0.2 ) 2 NiO 4 (LPNSBNO) exhibits a low polarization resistance of 0.29 Ω cm 2 at 700 °C. The single cell of LPNSBNO achieved a maximum power density of 0.82 W cm −2 in fuel cell mode. A current density of 0.58 A cm −2 was achieved in electrolyzer mode at 1.3 V and 700 °C. Furthermore, compared to Nd 1.6 Ba 0.4 NiO 4 , the entropy-enhanced LPNSBNO exhibits weaker Ba 2+ surface segregation energy, thereby demonstrating more robust Cr/CO 2 resistance. These results establish LPNSBNO as a catalyst with significant potential for bi-functional applications.
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PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2026
·
IF 9.2
Zheyan Tang,Hongwei Zhao,Lin Tao,Wenhao Liu,Lixiang Li,Yutong Shi,Jingang Zheng,Lin Wu,Han Zhang,Fang Di,Chengguo Sun,Zhihao Yao,Yanzhou Qin,Baigang An
Constructing iron-nitrogen-carbon (Fe- N -C) catalysts with high intrinsic activity for the oxygen reduction reaction (ORR) remains challenging. Meanwhile, additional structural optimization is necessary to improve mass transport and attain higher power density for practical applications. Herein, using silicalite-1 zeolite as a template, we employed a region-selective strategy to construct iron-embedded hollow-out nitrogen-doped carbon nanoboxes (Fe- N -HOCNs) catalyst with coexisted Fe-N x and Fe nanoclusters, and as an efficient ORR electrocatalyst for the zinc-air batteries (ZABs). Despite the Fe content of 4.73 wt% in Fe- N -HOCNs, it exhibits a high half-wave potential ( E 1/2 = 0.87 V), excellent mass activity ( j m , 658.17 mA mg −1 ), and turnover frequency (TOF, 0.3808 e − site −1 s −1 ), with ORR performance surpassing that of commercial Pt/C. This is attributed to the synergistic effect of coexisting Fe-N x and Fe nanoclusters, which effectively lower the energy barrier of the ORR, optimizes the adsorption of reaction intermediates, and enhances electronic conductivity. Moreover, the abundant short-range, penetrable microporous/mesoporous channels overcome the diffusion limitations of O 2 , significantly improving electrochemical wettability, accessibility, and utilization efficiency of the limited catalytic active sites, facilitating the exposure of active sites at the three-phase boundary. Finite element simulations reveal that the multidirectional hollow-out structure of Fe- N -HOCNs functions as interconnected pathways, substantially reducing O 2 transport resistance within the cathode catalyst layer. In ZABs, Fe- N -HOCNs enable the device to achieve a power density of 164 mW cm −2 and a specific capacity of 776 mA h g −1 , along with excellent rate performance.
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高影响因子
Small
·
2025
·
IF 12.1
Chengjie Chen,Xin Lai,Yongqi Jian,Dengke Zhang,Wenyu Huang,Jian Chen,Fangyan Xie,Yanshuo Jin,Ming-Hsien Lee,Guixiang Li,Nan Wang,Hui Meng,Mohammad Khaja Nazeeruddin
Iron and nitrogen co-doped FeNC catalysts with symmetric Fe-N 4 as the active site are the most promising alternative to noble metal catalysts for proton exchange membrane fuel cells (PEMFCs). However, the symmetric structure in the Fe–N 4 site endows oxygen intermediates with strong binding energy, which hinders the activity optimization of the active center. In this work, an asymmetric configuration (Fe-N 3 SC) is constructed to alleviate the electron localization caused by the d – π conjugation of Fe-N 4 . The asymmetric configuration can effectively reduce the splitting energy of the Fe-3d orbital, leading to a decrease in the energy barrier for the electrons to fill in the e g orbitals. Increased electron occupancy in the e g orbitals reduces the bond order/adsorption of the oxygen-containing intermediates on the active site, which leads to increased oxygen reduction (ORR) activity. The results of this work highlight the possibility of asymmetric configurations in manipulating and optimizing electron transfer and spin regulation of single-atom catalysts.
研究领域:
材料科学
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电催化
·
能量转换
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单原子催化
·
燃料电池
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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）