RSC Advances
·
2017
·Vol. 7
·期 59
·36867-36875
·
IF 3.108
Fangyan Liu,Jia Ni,Hui Hao,Wei Wang,Wei Chen,Lijie Zhang,Chao Zou,Yun Yang,Shaoming Huang
Pd-based nanostructures with stepped facets possess potential applications in many fields, particularly in catalysis. Generally, crystal growth often only allows the formation of nanostructures with energetically non-stepped facets, so it is desirable to develop methods that can be used to prepare Pd-based nanostructures bounded by stepped facets. Herein, penta-fold twinned (PFT) Au@Pd nanobipyramids (NBs) with stepped {100} facets were synthesized through growing Pd on Au decahedral nanoparticles (NPs) in polyol. During the growth of Au@Pd NBs, Br− was a critical factor, because it has appropriate affinity for the Pd atom and adjusted the growth rate ratio along 〈110〉 and 〈100〉, resulting in the formation of Au@Pd NBs with stepped {100} facets. The product shape and size could be tailored by controlling the reaction conditions. Transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), energy dispersive spectroscopy (EDS), high angle annular dark field (HAADF) imaging and scanning transmission electron microscopy EDS (STEM-EDS) were used to investigate the structure and growth of the Au@Pd NBs. A growth mechanism involving two stages was elucidated. In the first stage, the growth of Pd clearly occurred along both 〈110〉 and 〈100〉. In the second stage, the growth along 〈110〉 was faster than that along 〈100〉. Furthermore, we also demonstrated that the as-prepared Au@Pd NBs had high catalytic activity, compared with Pd nanocubes and Pd–Au–Pd segmental nanorods.
研究领域:
纳米材料化学
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催化科学
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无机合成
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表面科学
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电化学
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2025
·
IF 4.9
Wen Liu,Qian Su,Zifeng Yang,Mengqian Fu,Yifan Liu,Weiguo Cheng
Abtract The conversion of CO₂ into cyclic carbonates is a feasible approach for CO 2 mitigation. The environmentally friendly halide-free catalysts, which could avoid the waste halide contamination and industrial equipment corrosion are highly concerned. In this study, a series of halide-free ionic liquids with dual regulation of anion basicity and nucleophilicity were designed to achieve high catalytic efficiency. Among the synthesized ionic liquids, the [BmmIm][PA] demonstrated superior catalytic efficiency, delivering 94.9 % product yield with 99.9 % selectivity under the optimized conditions (70 °C, 2 mol%, 3.5 h, 10 bar). According to the deep activation energies analysis, the superior catalytic efficiency of [BmmIm][PA] was attributed to the strong nucleophilicity of [PA] reducing the ring-opening activation energy and the mild basicity of [PA] reducing the ring-closing activation energy simultaneously. The lower reaction activation energy catalyzed by [BmmIm][PA] was further confirmed by kinetic experiments. Finally, by combining DFT calculations with IR, NMR spectroscopy, a detailed catalytic mechanism involving direct epoxides activation by [PA], CO 2 insertion and ring-closing was proposed. This work provided a more comprehensive understanding of halide-free catalysts and laid a theoretical foundation for the green and efficient conversion of CO 2 .
研究领域:
绿色化学
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催化化学
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环境科学
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有机合成
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物理化学
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分子催化
·
二氧化碳利用
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2023
·Vol. 14
·期 1
·1-12
·
IF 16.6
Yang Xu,Zhang Bao,Tian Yao,Wang Yao,Fu Zhiqiang,Zhou Dong,Liu Hao,Kang Feiyu,Li Baohua,Wang Chunsheng,Wang Guoxiu
Rechargeable halide-ion batteries (HIBs) are good candidates for large-scale due to their appealing energy density, low cost, and dendrite-free features. However, state-of-the-art electrolytes limit the HIBs’ performance and cycle life. Here, via experimental measurements and modelling approach, we demonstrate that the dissolutions in the electrolyte of transition metal and elemental halogen from the positive electrode and discharge products from the negative electrode cause the HIBs failure. To circumvent these issues, we propose the combination of fluorinated low-polarity solvents with a gelation treatment to prevent dissolutions at the interphase, thus, improving the HIBs’ performance. Using this approach, we develop a quasi-solid-state Cl-ion-conducting gel polymer electrolyte. This electrolyte is tested in a single-layer pouch cell configuration with an iron oxychloride-based positive electrode and a lithium metal negative electrode at 25 °C and 125 mA g –1 . The pouch delivers an initial discharge capacity of 210 mAh g –1 and a discharge capacity retention of almost 80% after 100 cycles. We also report assembly and testing of fluoride-ion and bromide-ion cells using quasi-solid-state halide-ion-conducting gel polymer electrolyte.
研究领域:
材料科学
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电化学
·
能源存储
✓ 已验证
DOI
PubMed
高影响因子
Journal of Nano Research
·
2016
·
IF 0.366
Qing Quan Guo,Xin Fu Ma,Hai Xiang Ma,Yao Lu
The preparation of size- and shape- controlled metallic nanoparticles using biological methodologies is a noticeably stimulating research field due to their unique physicochemical properties. In this paper, biosynthesis of anisotropic AuNPs using Ampelopsis grossedentata extract and the effects of halide ions on the formation of AuNPs has been demonstrated. The sizes and morphologies of AuNPs were characterized by UV-vis-NIR spectrophotometer and Transmission Electron Microscopy (TEM). It showed that the shape, size and optical properties of AuNPs can be fine-tuned by varying the dosage of the vine tea extract. The presence of halogen ions has significantly influence the morphology of AuNPs during the synthesis process. Both of Br- and Cl- could produced nanoplates, whereas I- distorted the triangle nanoparticles to induce the formation of aggregated spherical ones.
研究领域:
纳米技术
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材料科学
·
生物技术
·
化学
✓ 已验证
DOI
高影响因子
Greenhouse Gases-Science and Technology
·
2023
·
IF 2.2
Zifan Xing,Haitao Chen,Min Mao,Xiaocen Liang,Da Song,Yang Li,Tao Long,Xiaoli Chen,Fang He
The chemical looping oxidative dehydrogenation (CL-ODH) of ethane represents a highly effective approach for converting ethane into the value-added product ethylene. This investigation focused on the synthesis of SrMnO 3 and its halide ions doped derivatives (SrMnO 3 Cl and SrMnO 3 Br) through the sol-gel method. The performance of these perovskites, employed as oxygen carriers in CL-ODH of ethane, was explored. The results unveiled several advantageous outcomes arising from the incorporation of halide ions (Cl − and Br − ) with larger radius into the oxygen sites of the SrMnO 3 perovskite. Halide ions doping notably induced cell volume expansion and enhanced lattice fringe spacing. Furthermore, it contributed to elevated oxygen vacancy concentration, increased Mn 4+ /Mn 3+ molar ratio, and improved oxygen ions mobility within the bulk lattice. Fixed-bed experiments demonstrated that these redox catalysts, doped with halide ions, exhibited outstanding activity and stability during cycling tests, exhibiting enhanced both ethylene selectivity and yield in CL-ODH of ethane. In summary, the introduction of halide ions into SrMnO 3 emerges as a promising strategy for enhancing the performance of CL-ODH in ethane conversion for SrMnO 3 based oxygen carriers. © 2023 Society of Chemical Industry and John Wiley & Sons, Ltd.
研究领域:
化学工程
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催化
·
材料科学
✓ 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）