ELECTROCHIMICA ACTA
·
2024
·
IF 5.5
Yuhui Wang,Tong Zhang,Yong Huang,Shaonan Gu,Shu Zhang,Zhi Wang,Junhao Liu,Xuzhong Gong
Precise regulation of oxygen reduction reaction (ORR) for 2e-ORR or 4e-ORR is of great importance in designing efficient catalysts for electrochemical reactions. Currently, the exact roles of the functional groups and their possible synergistic functions still remain controversial. In this work, catalysts with different combinations of N and O functional groups were prepared using graphite to regulate ORR selectivity. Meanwhile, the quantum chemical parameters of various functional group combinations in the literature were summarized by using DFT calculation, and a method was provided to explain the relationship between functional group combinations, electronic structure and ORR selectivity by HOMO orbital delocalization index (ODI H ) and Mulliken population (MP). Finally, combining the molecular level calculations, a close correlation between the molecular structures with the tendency of 2e-ORR or 4e-ORR was established. Among them, the combination of C=O, N-Graphitic and Pyridinic-Pyrrolic-Graphitic nitrogen structure promoted 4e-ORR. C-O, O=C-O, N-Pyridinic and N-Pyrrolic promoted 2e-ORR. This study has revealed the essential difference between 2e-ORR and 4e-ORR, and provided a direction for determining the structure of 2e-ORR or 4e-ORR catalysts.
研究领域:
材料科学
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电化学
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产品关联
DOI
高影响因子
Advanced Sustainable Systems
·
2021
·Vol. 6
·期 1
·2100343
·
IF 6.271
Yinghui Li,Yuanju Qu,Chaocheng Liu,Jiedong Cui,Ke Xu,Yang Li,Haoyu Shen,Zhouguang Lu,Hui Pan,Tao Xu,Detao Liu
Bifunctional oxygen reduction/oxidation reaction (ORR/OER) electrocatalysts derived from biomass are one of the most valuable materials in terms of sustainability, ecological economy and industrial manufacturing, and are emerging as a desired alternative to the commercial Pt/C and IrO 2 catalysts. This work demonstrates the processing of agricultural cornstalk waste of cornstalks into stable bifunctional ORR/OER catalysts with high-performance by a simple and cost-effective strategy. Rich hydrophilic active groups (e.g., hydroxyl groups) in the hierarchical porous structures of the native cornstalks enable the sufficient facile combination with transition metals (e.g., Co, Fe, Zn) and heteroatoms (e.g., B, N) from soluble Co(NO 3 ) 2 , ZnCl 2 , H 3 BO 3 , NH 4 Cl in a hydrothermal reaction. The pyrolytic evaporation of Zn 2+ in a high-temperature carbonization process facilitates the generation of abundant micropores and mesopores to increase specific surface areas (941.44 m 2 g −1 ) and also hinders aggregation between neighboring transition metals. The synergistic effects of N, B, Fe and Co doping in hierarchical porous biochar-structures contributes to outstanding bifunctional ORR/OER activities and working stabilities, outperforming commercial Pt/C and IrO 2 catalysts. Computational results further verify the valuable synergistic contributions based on density-functional theory (DFT). This approach opens up a new possibility for the fabrication of bifunctional biochar-based ORR/OER catalysts from artificial engineering and green processing for sustainable agricultural wastes.
研究领域:
材料科学
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能源科学
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环境科学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2025
·
IF 8.3
Daming Yang,Yingyue Zhang,Jiaqi Sun,Xinyu Zhang,Ze Gao,Qilong Sun,Tong Wu,Wei Lu,Guiru Sun,Ming Feng
The photo-assisted strategy is viewed as a promising method to improve the ORR and OER performance of Li–O 2 batteries. Nevertheless, designing a photocatalyst that ensures wide light absorption and minimizes the recombination of photoinduced electrons and holes is still a notable challenge. In this study, 2D porous Co 3 O 4 nanosheets are synthesized as photocatalysts for photo-assisted Li–O 2 batteries. Their unique structure improves surface area, facilitates O 2 transport, and stores discharge products. Equally, the Co 3 O 4 nanosheets exhibit strong light responsiveness and photocatalytic activity. Upon optical field, photoinduced electrons and holes are successfully separated on Co 3 O 4 nanosheets, which promotes the formation and decomposition of Li 2 O 2 , respectively. Li–O 2 cells using Co 3 O 4 nanosheets display a low overpotential of 0.15 V and good cycling stability under optical field. These findings highlight the potential of Co 3 O 4 nanosheets as photocatalysts for photo-assisted Li–O 2 batteries, providing a foundation for future energy storage advancements.
研究领域:
材料科学
·
能源化学
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Tianyan Lan,Hongmei Du,Yunwu Li,Konggang Qu,Jinsheng Zhao,Xianxi Zhang,Yunyun Dong,Yan Zhang,Xueyue Zhang,Danyang Zhang
The development of bifunctional electrocatalysts to reduce the polarization loss is essential to enhance the performance of Zn-air batteries. The combination of metal-organic frameworks (MOFs) with metal or metallic compounds provides a way to integrate their merits and effectively improve their electrocatalytic performances. However, previous synthesis of MOFs/metal oxides usually involves high-temperature calcination , which makes it difficult to control their morphologies. In this work, through a ligand-insufficient and high temperature controlled solvothermal reaction, innovative NiFe-MOF/NiFe 2 O 4 hollow nanospheres were one-pot prepared without using any shape-controlled agent or calcination process. The as-obtained NiFe-MOF/NiFe 2 O 4 shows better ORR and OER performance than pure NiFe-MOF and NiFe 2 O 4 , suggesting a synergetic effect between NiFe-MOF and NiFe 2 O 4 . The maximum power density of the liquid Zn-air battery assembled using NiFe-MOF/NiFe 2 O 4 as the air electrode catalyst is 158.4 mW cm −2 at 246.1 mA cm −2 . This work offers fresh thoughts into designing highly efficient MOF-derived electrocatalysts.
研究领域:
材料科学
·
电化学
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Yingchao Wang,Jingjing Wu,Xianglong Lu,YuMin Guo,Huining Zhao,Xin Tang
The bifunctional catalysts which can improve both oxygen evolution (OER) and oxygen reduction reaction (ORR) activity are highly desirable for fuel cells, metal-air batteries and water splitting. Here, we report a perovskite structure Sr 0.9 M 0.1 RuO 3-δ (SMRO, M=K, Na, Ag) synthesized via sol-gel method performing excellent bifunctional catalytic activity. With the metal ion (M + ) doping in A-site, X-ray photoelectron spectroscopy analysis reveals that oxygen vacancy and lattice oxygen are introduced into the structure, which is confirmed as the primary reason for the improvement of catalytic activity. The highest OER and ORR activity among these four samples is observed in Sr 0.9 Ag 0.1 RuO 3 (SARO). This work may shed light on the designing of high-efficiency bifunctional OER/ORR electrocatalysts .
研究领域:
材料科学
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电化学
✓ 已验证
DOI
高影响因子
CATALYSIS TODAY
·
2025
·
IF 5.3
Xi Shen,Zhenyu Zhao,Hong Li,Xin Gao
The recycling and upcycling of waste plastics into high-value products by pyrolysis is a critical challenge caused by its time/energy-consuming problems, which can be overcome by employing microwave-assisted catalytic pyrolysis due to its rapid pyrolysis rates and high product yields. This study presents a facile method for the synthesis of catalysts for microwave-assisted pyrolysis of waste plastics, utilizing the pyrolytic products as raw materials. In this case, a microwave thermal shock strategy is developed to efficiently anchor iron nanoparticles on carbon nanotubes (CNTs). This method recycles a portion of pyrolysis products back into the catalyst pool for plastic transformation into new CNTs, reducing the consumption for preparing additional catalysts. The precursors exposed to 50 W microwave irradiation reaches above 2000 °C within seconds, allowing Fe nanoparticles to be uniformly impregnated within the carbon nanotube matrix. The formed iron-doped CNTs shows high activity for microwave-assisted pyrolysis, generating CNTs with D/G ratios at 0.31. The recycling and reconstruction of CNTs after multiple pyrolysis form a cross-lined network structure, which facilitates electron transition and can be utilized for fabricating electrocatalysts. Nitrogen doping further improves the onset potential to 0.923 V vs. RHE, making them viable candidates for electrocatalytic applications in oxygen reduction reactions. In summary, our findings demonstrate the feasibility of this approach to reactive pyrolysis products that serve as catalysis for microwave-assisted pyrolysis, with the potential to reduce volatile organic compound emissions and capital expenditure in catalyst preparation, offering a greener and more efficient pathway for plastic waste management and catalyst production.
研究领域:
材料科学
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环境科学
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化学工程
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产品关联
DOI
高影响因子
Materials Today Energy
·
2022
·
IF 9.257
Kaiyue Chen,Xingkun Wang,Canhui Zhang,Ren Xu,Huanlei Wang,Lei Chu,Minghua Huang
Breakthroughs in the design of robust bifunctional oxygen reduction/evolution reaction (ORR/OER) catalysts could put Zn–air batteries performance to the summit but remain full of challenges. In this work, the MnS phase was deliberately introduced into the Mott–Schottky Co/Co 9 S 8 for engineering a three-phases Co/Co 9 S 8 /MnS heterojunction on defect-rich N-doped mesoporous carbon substrate (Co/Co 9 S 8 /MnS-NMC). It affords abundant three-phases heterostructure interfaces that effectively accelerate the electron transfer and trigger further electronic structure reconfiguration, thus advancing the bifunctional ORR/OER activities. Benefiting from these structures, the Co/Co 9 S 8 /MnS-NMC possesses a half-wave potential of 0.84 V toward ORR and a low overpotential of 330 mV toward OER at a current density of 10 mA/cm 2 , catching up with those of commercial Pt/C and RuO 2 catalysts. It also endows the Zn–air batteries with a good power density, round-trip efficiency, and robust stability over 750 h, showcasing the promising potential in practical applications. This work not only provides a facile strategy to construct the three-phases heterojunction catalysts but also sheds light on developing the efficient and robust nonprecious metal-based bifunctional ORR/OER catalysts.
研究领域:
材料科学
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电化学
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DOI
高影响因子
JOURNAL OF CATALYSIS
·
2019
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IF 7.723
Lian-Hua Xu,Hai-Bo Zeng,Xue-Ji Zhang,Serge Cosnier,Robert S. Marks,Dan Shan
Tuning the coordination environment between metal centers and organic ligands is a promising way to design of the precursors of electrocatalysts for water splitting or other renewable energy options. In this work, a novel coordinated polymer was prepared feasibly in polyvinyl pyrrolidone (PVP) aqueous solution using aminotrimethylene phosphonic acid (ATMP, L 1 ) and 2-methylimidazole (MeMI, L 2 ) as ligands with the ratio of 2:5, Co 2+ and Zn 2+ as metal centers. Based on the concept of acid-base neutralization reaction, the proton-transfer induced “deprotonation and protonation” for L 1 and L 2 , respectively. Thus, the coordination was dominated by the deprotonated L 1 . Owing to also partial of protonated L 2 adsorbed as “counter ions”, carbonization of the obtained precursor at 800 °C under N 2 atmosphere endows the pyrolysis product with nitrogen-doped carbon supported metal pyrophosphate (M 2 P 2 O 7 @NC). Thus, the resulting M 2 P 2 O 7 @NC exhibits the enhanced and durable ORR and HER performance. For ORR in 0.1 M KOH, an enhanced onset potential (0.925 V vs. RHE), half wave potential (0.793 V vs. RHE) and diffusion limiting current (6.132 mA cm −2 ) can be obtained comparable to those of Pt/C. For HER in 0.5 M H 2 SO 4 , it only needs an over potential of 180 mV to realize a current density of 10 mA cm −2 .
研究领域:
材料科学
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能源化学
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产品关联
DOI
高影响因子
CARBON
·
2020
·
IF 8.821
Jintao Zhang,Tong Zhang,Jing Ma,Zhi Wang,Junhao Liu,Xuzhong Gong
Two-step carbonization method was reported to synthesize Co–N doped coal tar pitch (CTP) carbon-based electrocatalysts with hierarchical pore structure , high local order degree and efficient Co-N x active structure simultaneously. The synergistic effect of the carbon substrate with highly ordered structure and the Co-N x active sites realized the “Point discharge effect”. The π-π interactions from the CTP aromatic ring sheets and Co-N x promoted the adsorption and dissociation of oxygen molecules, respectively. The increased diffusion coefficient ( D 0 ) indicated the mass transfer of oxygen molecules in the boundary layer was enhanced during the ORR process. Thanks to excellent structural characteristics, ACTP 5 @Co,N-800 exhibited better ORR performance than commercial Pt/C catalyst under alkaline conditions, and the OER activity was improved simultaneously. This work demonstrated a simple and practical strategy for the development of advanced carbon-based electrocatalysts, and also provided novel insights from kinetics perspectives for improving electrocatalytic efficiency.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
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
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
·
催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2022
·
IF 7.139
Jiaxian Liu,Xinyu Fan,Guyang Ning,Man Zheng,Kun Shi,Yuena Sun,Yongjun Gao,Yufan Zhang,Huan Wang
High-efficiency and economical electrocatalysts for electrochemical water splitting are the core component of the renewable energy conversion. Herein, a simple and economical strategy is described to synthesize a series of metal oxide decorated nitrogen-doped carbon nanotubes materials (N-CNT@Cu–Fe Oxide Alloy NPs) by utilizing carbon nanotubes as the substrate carrier material. Additionally, the polypyrrole (PPy) was served as both the nitrogen resource and the localizing agent to load the Cu–Fe oxide alloy. Moreover, the theoretical and test results indicated that the superior HER and ORR performance is mainly related to the synergistic effect between the nitrogen-doped CNT and metallic oxide alloy. In the series of catalysts we prepared, N-CNT@Cu 1 –Fe 1 Oxide Alloy NPs exhibits more significant catalytic activity and better durability than other catalysts that we synthesized. Meanwhile, the catalyst shows the low Tafel slope of 68.28 mV dec −1 for HER and reaches 10 mA cm −2 at the overpotential of 375 mV. The K–L plot shows that the electron transfer number of N–CNF@Cu 1 –Fe 1 Alloy NPs is 3.43.
研究领域:
电化学
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材料科学
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催化
·
可再生能源
✓ 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）