APPLIED CATALYSIS B-ENVIRONMENTAL
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2023
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IF 22.1
Lina Yan,Chao Wang,Yueshuai Wang,Yahui Wang,Zhaozhao Wang,Lirong Zheng,Yue Lu,Ruzhi Wang,Ge Chen
Electrochemical production of hydrogen peroxide (H 2 O 2 ) is a sustainable and environmentally benign process. The electrochemical oxygen reduction process (ORR) via a two electron pathway (2e - ORR) offers a practical method for on-site H 2 O 2 generation. As an earth-abundant catalyst, the cobalt-nitrogen coordinated systems integrated into the carbon matrix (Co-NC) has caused wide attention for its high activity in 2e - ORR. Even though most of the reported Co-NC catalysts have classical planar Co-N 4 coordination, axial coordination engineering has recently emerged as an effective way to control the active sites in the axial direction by using different coordination ligands. The structure-function link between the Co-N configuration of non-planar coordination and 2e - ORR activity is, however, not fully understood. An axial-N coordinated Co-N 5 motif embedded in hierarchically porous graphite-3R carbon (Co-N 5 C) was effectively synthesized using a template-sacrificing method. The Co-N 5 C has a high selectivity for 2e - ORR and a high H 2 O 2 molar production rate of up to 6.78 mol peroxide/g catalyst /h in acidic media, both of which are better than its Co-N 4 counterpart. DFT analyses demonstrate that axial-N ligands regulated the d -band center of the Co atom in the Co-N 5 C catalyst, inducing a shift in Δ G *OOH near the Sabatier volcano plot's peak (Δ G *OOH = 4.22 eV). This optimized the binding of the *OOH intermediate and then enhanced the protonation of *OOH to produce H 2 O 2 more efficiently.
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
NANOTECHNOLOGY
·
2023
·Vol. 34
·期 44
·445601
·
IF 3.5
Shuyuan Xu,Bingbao Mei,Fengjiao Li,Jianing Mao,Changxing Huang,Yufeng Yan,Ningning Chen,Yinghua Xu,Meiqin Shi
The application of electrochemical hydrodechlorination has been impeded due to the low utilization and activity of Pd catalyst. Herein, a series of Pd catalysts were prepared via the controllable evolution of Zn state during the pyrolysis of ZIF-8 nanosheet. Various forms of Pd with different chemical surroundings were generated upon the combined use of galvanic displacement and ion exchange process. Electrocatalytic hydrodechlorination of 4-chlorophenol was performed and the electrocatalytic hydrodechlorination efficiency of Pd/CN reaches 100% within 3 h at extra low Pd concentration. The coexistence of zero-valent Pd (Pd0) and nitrogen coordinated Pd (Pd–N) was verified by XAFS which provide multiple active sites for focusing on adsorbing H* and cracking C–Cl respectively. The synergetic effect between different chemical state of Pd for efficient hydrodechlorination of chloroaromatics and scheme for dexterous preparation of Pd based electrocatalyst are proposed and discussed.
研究领域:
环境科学
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催化化学
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2023
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IF 13.1
Yuan Qin,Chaozhong Guo,Zihao Ou,Chuanlan Xu,Qi Lan,Rong Jin,Yao Liu,Yingchun Niu,Quan Xu,Yujun Si,Honglin Li
Designing single-atom catalysts for oxygen reduction reaction (ORR) are fashionable but challenging to boost the zinc-air battery performance. Significantly enhanced ORR activity by manganese (Mn) single-atom catalysts can be achieved by accurately regulating the coordination number of isolated Mn atoms. Theoretical calculations indicate that the single Mn-N 5 sites possess lower free energy barrier and higher oxygen adsorption performance than single Mn-N 4 sites to accelerate the ORR kinetics. Target to it, here we synthesize an atomically dispersed Mn-N 5 catalyst by precisely axial coordination of pyridinic-N doped into two-dimensional (2D) porous nanocarbon sheets (∼3.56 nm thickness), which reveals outstanding catalytic activity and ultrahigh stability for the ORR in zinc-air battery owing to the inhomogeneous charge distribution of Mn-N 5 sites compared to the conventional single-site Mn-N 4 catalyst and Pt/C. This work gives a new strategy for in situ regulating the electronic structure of metal single-atoms and further promoting the overall ORR performance in energy systems.
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
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2020
·Vol. 44
·期 29
·12850-12856
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IF 3.288
Shice Wei,Fan Zhang,Zhenying Chen,Junjie Ding,Bai Xue,Chenbao Lu
The development of non-noble, efficient, and durable catalysts to replace expensive Pt-based catalysts for boosting the oxygen reduction reaction (ORR) is always an imperative and challenging topic. Herein, a triazine-linked covalent framework was prepared by using a cobalt-centered porphyrin derivative via a facile ionothermal approach, which was readily converted to a series of porous carbons (termed Co/N-PCs) with high surface areas upon controlled thermal treatment. The cobalt atoms coordinated with nitrogen were uniformly dispersed within the resulting porous structures. Accordingly, such as-prepared Co/N-PCs exhibited high activity for the ORR with a positive onset potential of 0.91 V (vs. RHE) and half-wave potential of 0.83 V, as well as good methanol tolerance and long-time durability. When used as air cathodes for Zn–air batteries, high power density (158.9 mW cm−2) and specific capacity (797 mA h g−1) were achieved, outperforming commercial Pt/C.
研究领域:
材料科学
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电化学
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能源科学
✓ 已验证
DOI
高影响因子
POLYMER
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2022
·
IF 4.432
Wenjuan Zhou,Shihong Ren,Fan Zhang,Xingchen Gao,Kai Song,Huagao Fang,Yunsheng Ding
Polyurethane elastomer nanocomposites are strategically important due to their indispensable applications in daily life and high-tech fields. Herein, a series of nanocomposites with extraordinary strength , toughness and energy dissipation are reported, which are enabled by multiple dynamic moieties including dynamic boronic ester covalent bonds , boron-nitrogen coordination bonds in the matrix and on the interface. The surface-modified silica nanoparticles with amino-silane coupling agent (D-SiO 2 ) were added to the polyurethane matrix that contains boron-nitrogen coordination. The presence of interfacial coordination significantly improves the dispersion of D-SiO 2 and enhances the interface interaction of polyurethane composites (SPU/D-SiO 2 ), which is evidenced by scanning electron microscopy, transmission electron microscopy and rheological investigation. Through mechanical experiment analysis, these modified polyurethane composites exhibit high tensile strength and toughness. The tensile strength of SPU/10D-SiO 2 increases to 19.5 ± 0.2 MPa and its tensile toughness achieves 216.9 MJ/m 3 , which is 35% of increase as compared with the pristine SPU that had a record-high toughness. In addition, the coordination bonds in the matrix and interface in the composites provide versatile and efficient energy dissipation during the tensile process. This work offers a facile method to improve the mechanical robustness of the newly developed supramolecular polyurethane elastomers.
研究领域:
材料科学
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高分子化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 9
·期 17
·11025-11032
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IF 12.732
Zhiwei Guo,Chunyang Bao,Xiaohan Wang,Xingyuan Lu,Haoxiang Sun,Xiang Li,Jian Li,Junqi Sun
Mechanically robust polyurethanes and polyureas with excellent healing and recycling capacities have an extended service life, and can reduce raw material consumption and environmental pollution. In this work, healable, recyclable and mechanically super-strong poly(urea-urethane)s (PUUs) are conveniently fabricated via cross-linking isocyanate-terminated poly(tetramethylene ether glycol) (PTMEG) with nitrogen-coordinated boroxines (NCBs). The tripodal NCBs generate three-dimensionally cross-linked PUUs (denoted as NCB-PUUs) with a high cross-linking density. Meanwhile, hydrogen bonds and phase-separated PTMEG segments can serve as physical cross-linkers to further strengthen NCB-PUUs. As a result, the NCB-PUUs exhibit a tensile strength of ∼47 MPa and a toughness of ∼190 MJ m−3. Because of the high reversibility of NCBs and hydrogen bonds, the NCB-PUUs are capable of efficiently healing and recycling at room temperature with the assistance of ethanol or a water/ethanol mixture to restore their original mechanical strength. NCB-PUUs can be conveniently deposited on solid surfaces by dip-coating and spraying methods to serve as protecting coatings. The NCB-PUU coatings have firm adhesion on solid surfaces and can be doped with organic dyes to display diverse colors. More importantly, the NCB-PUU coatings can heal deep and wide cuts and scratches for multiple times in a given region.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Nano
·
2023
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IF 17.1
Haoyang Fu,Ke Li,Chenfei Zhang,Jianghong Zhang,Jiyuan Liu,Xi Chen,Guoliang Chen,Yongyang Sun,Shuzhou Li,Lan Ling
Machine learning (ML) algorithms will be enablers in revolutionizing traditional methods of materials optimization. Here, we broaden the use of ML to assist the construction of Fenton-like single-atom catalysts (SACs) by developing a methodology including model building, training, and prediction. Our approach can efficiently extract synthesis parameters that exert a substantial influence on Fenton activity and accurately predict the phenol degradation rate k of SACs with a mean error of ±0.018 min–1. The extended synthesis window with accelerated learning enables the realization that the heating temperatures during SAC synthesis significantly influence the Fe–N coordination number, which ultimately dictates their performance. Through ML-guided optimization, a highly efficient SAC dominated by Fe–N5 sites with exceptional Fenton activity (k = 0.158 min–1) is identified. Our work provides an example for ML-assisted optimization of single-atom coordination environments and illuminates the feasibility of ML in accelerating the development of high-performance catalysts.
研究领域:
材料科学
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环境科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2021
·
IF 5.816
Wei-Chang Chen,Gang Yang,Yue Zhao,Gao-Qing Yuan,Jian-Shan Ye,Hai-Yang Liu,Xin-Yan Xiao
This work has manufactured a series of M-N X /C (M = Fe, Cu, Ni) ORR catalysts by the pyrolysis of metal tetraphenylporphyrin (MTPP) adsorbed onto N-doped porous carbon polyhedrons (NPCP) derived from ZIF-8. The comprehensive characterization data shows that the prepared M-N X /C catalysts have hierarchical porous structure with high specific surface area and abundant M-N X moieties. All prepared M-N X /C catalysts exhibit good ORR performance. The ORR half-wave potentials E 1/2 of Fe-N X /C, Cu-N X /C and Ni-N X /C catalyst are 0.885, 0.801 and 0.755 V respectively. The rotating ring-disk electrode (RRDE) test reveals that the ORR of Fe-N X /C is a four electron process. While a two and four electron mixing ORR process are observed for Cu-N X /C and Ni-N X /C. In an alkaline medium , E 1/2 of Fe-N X /C is observed 44 mV higher than that of commercial Pt/C. Also, Fe-N X /C catalyst has outstanding long-term durability and good methanol resistance.
研究领域:
材料科学
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电化学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2023
·
IF 6.6
Sun Lina,Sun Liping,Huo Lihua,Zhao Hui
The production of hydrogen peroxide (H 2 O 2 ) through electrochemically reducing O 2 in a two-electron pathway is a potential substitute for the traditional process based on anthraquinone. In this paper, F doping is carried out to prepare N and F co-doped porous carbon embedded Co nanoparticles. The electro-catalytic activity for the electrochemical production of H 2 O 2 is systematically investigated. The composite material demonstrates exceptional electro-catalytic selectivity, reaching approximately 92.5%, and shows an ultra-high rate of producing H 2 O 2 in 4021.4 mmol g -1 h -1 at 0.1 V versus RHE in a 0.5 M H 2 SO 4 electrolyte. It is found that the synergetic effect of Co-Nx and F in the composite material result in its exceptional performance. Adding F atom modulates the Zeta potential of the catalyst and alters the electronic configuration around Co-Nx, creating favorable conditions for the uptake of O 2 and consequently forming OOH*. Additionally, the highly electronegative F atom facilitate desorbing OOH* through electrostatic repulsion, preventing any further degradation. In a homemade electrolyzer containing 80 mg L -1 of Rh B, the H 2 O 2 produced in situ in a 0.5 M H 2 SO 4 electrolyte degrades up to 97.76% of Rh B in just 22.5 min, showcasing its potential for practical wastewater treatment applications.
研究领域:
材料科学
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环境科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2022
·Vol. 169
·期 10
·106507
·
IF 4.386
Mengxue Huang,Ruimin Ding,Jie Yang,Wenwen Shi,Shufang Shi,Lifang Chen,Shanshan Liu,Xi Yin
Platinum group metal-free catalysts based on transition metal and nitrogen co-doped carbon materials are gaining attention for their applications in electrocatalysis. Nitrogen-coordinated metal sites (MNx) have been identified as the main active sites in PGM-free catalysts. Current synthetic approaches rely on the high-temperature treatment to introduce targeted electroactive MNx sites into the carbon matrix. In this study, we demonstrated the formation of MNx sites on Ni- and N-co-doped carbon templates via the solution-phase coordination with target metal ions, including Fe2+, Fe3+, and/ Co2+. The formation of MNx sites was confirmed via a combined approach of various physical characterization techniques, elemental analysis, and electrochemical analysis. The results indicate that the metal-vacancy-Nx sites in the template can coordinate with target ions to form electrochemically active MNx sites. By varying heat-treatment temperature, the amount of FeNx sites formed via coordination with Fe2+ ion can be tuned and correlated with the change of activity toward oxygen reduction reaction. The amount of MNx sites formed via solution-phase coordination with various ions followed the sequence of Co2+ > Fe2+ > Fe3+. These findings may further guide the future development of MNx-C electrocatalysts through this solution-phase coordination approach.
研究领域:
材料科学
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电化学
✓ 已验证
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Yuxiang Mao,Jun Cheng,Hao Guo,Lei Qian,Yang Xu,Jiacan Tu,Weijuan Yang
To strengthen active sites in zeolitic imidazolate frameworks (ZIFs) to effectively convert microalgal lipids into biodiesel, acid-base bifunctional single-atom catalysts with Zn-N x coordination were synthesized through pyrolyzing ZIF-8. The saturated coordinated Zn-N 4 sites were destroyed and converted to unsaturated coordinated Zn sites and surrounding N atoms at 700 °C, which enhanced Lewis acidity and basicity, respectively. The Zn-N content in the catalyst decreased from 77.68 % to 43.26 %, while that of pyridinic N increased from 8.14 % to 36.73 %. The acidity of the catalyst increased from 0.498 to 3.979 mmol/g, whereas basicity increased from 0.219 to 0.650 mmol/g. According to density functional theory calculations, unsaturated coordinated Zn-N x (x = 1, 2, 3) sites exhibited lower free energies and reaction energy barriers in free fatty acid esterification. The energy barriers for rate-determining steps over Zn-N 4 , Zn-N 3 , Zn-N 2 , and Zn-N 1 sites were + 1.01 eV, +0.82 eV, +0.63 eV, and + 0.54 eV, respectively. Therefore, the optimum catalyst exhibited a high conversion efficiency of 97.9 %, which was better than that of ZIF-8 (85.4 %).
研究领域:
化学工程
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催化材料
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2024
·
IF 4.1
Huagao Fang,Yongpu Zhao,Xingyu Xie,Fan Zhang,Xinyu Xie,Jiaji Zhu,Shihong Ren,Yunsheng Ding
Malleability and reprocessability of cross-linked polymers can be achieved via exchange reactions of the boronic ester crosslinking. Herein, we report a facile strategy to fabricate and modulate vitrimers by introducing intermolecular boron-nitrogen coordinated boronic ester crosslinking. Using a one-pot reaction, a series of boronic ester vitrimers based on polybutyl acrylate (PBA) was synthesized. The nitrogen containing monomer dimethylaminoethyl methacrylate (DMAEMA) was successfully copolymerized in the backbone to generate intermolecular boron-nitrogen (B–N) coordination. The presence of B–N coordination increases intermolecular interactions, leading to a denser crosslinked network structure and an elevated glass transition temperature. With the formation of B–N coordination, PBA-xB-yN samples at the same crosslinking density exhibit higher elongation at break and tensile strength. These samples dissipate more energy at the same strain and show a more pronounced strain rate dependency, highlighting the sacrificial role of the B–N coordination bonds. Stress relaxation experiments reveal that the intermolecular B–N coordination promotes faster relaxation of PBA-xB-yN compared to PBA-xB due to accelerated exchange dynamics of boronic ester. Mechanical reinforcement after recycling is observed in PBA-1B–2N, indicating that structural optimization of chemical and physical crosslinking occurs during thermal reprocessing. This study will provide a new strategy to fabricate boronic ester based vitrimeric materials with mechanical reinforcement and toughness enhancement.
研究领域:
材料科学
·
高分子化学
✓ 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）