FUEL
·
2024
·
IF 6.7
Zhixian Bao,Dekang Li,Zhiheng Wang,Yuxin Wen,Lijun Jin,Haoquan Hu
The lack of detailed functions of different REMs in NH 3 decomposition to H 2 makes the efficient modified catalysts not rationally be designed though many REMs-modified catalysts have been reported. In this work, the 10Ni/A 1 Mg 4 O α (A = La, Ce, and Y) and 10Ni/MgO, in which supports were synthesized by the sol–gel method and Ni was loaded by the wet-impregnate method, were comparatively investigated to reveal the effect of REMs against NH 3 decomposition reaction. The presence of REMs enhanced the activity of 10Ni/A 1 Mg 4 O α and decreased the activation energy as greatly as by half compared to 10Ni/MgO. The produced H 2 in situ has little impact on the activity of 10Ni/A 1 Mg 4 O α , among which Ce has the most excellent H 2 desorption ability. The intrinsic activity of catalysts was improved better by Ce and Y than La and the best Ni particle size is around 6 nm according to TOF, though the Ni particle is the smallest (4.9 nm) in 10Ni/La 1 Mg 4 O α . The surface structure of catalysts was tuned by doping REMs, forming a solid solution and some defects (oxygen vacancies), which enhanced the interaction between active metal and support with obvious electron transfer from support to Ni obtaining a better Ni dispersion and making NiO easier to be reduced. Additionally, the catalysts doped by La or Ce possess more oxygen vacancy due to the changes of La 2 O 2 CO 3 and the valence of Ce, exhibiting stronger basic sites and better N 2 desorption capacity. The study offers a promising strategy for utilizing appropriate or multiple REMs to synthesize effective catalysts effectively for catalyzing NH 3 decomposition in the future.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Shuya Rui,Na Liu,Lingwei Ren,Yang Liu,Zian Liu,Binghui Wu,Hua Pan,Zhiping Ye
Traditional Mn-Ce catalysts for selective catalytic reduction (SCR) of NO with CO (CO-SCR) in iron and steel flue gases are often hindered by competitive adsorption of NO and CO, which compromises catalytic efficiency. In this study, we present a Ni-doped Mn-Ce catalyst that overcomes these challenges, achieving 96 % NO conversion, 98 % N 2 selectivity, and 44 % CO conversion at 175 °C. Comprehensive characterization of the catalyst reveals that Ni doping significantly enhances Mn-Ce interactions, boosting oxygen vacancy density and promoting efficient redox cycling between Mn 3 + /Mn 4+ and Ce 3+ /Ce 4+ . Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) confirms preferential NO adsorption at oxygen vacancy sites, minimizing CO-NO competition and stabilizing the Langmuir-Hinshelwood mechanism, where both gases co-adsorb and react at oxygen-rich vacancies. Mechanistic insights suggest that Ni facilitates electron transfer, weakening the N–O bond in NO and accelerating its dissociation, resulting in faster NO reduction. This study establishes Ni doping as a promising strategy for improving the low-temperature performance of Mn-Ce-based CO-SCR catalysts, paving the way for more efficient catalytic systems.
研究领域:
催化化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2013
·Vol. 40
·期 1
·385-397
·
IF 0.88
Wang Yong,Chen Guihua,Zhang Fumin,Li Liquan
Ni-incorporated SBA-15 magnetic composites were two-stage hydrothermal synthesized from initial strong acidic media through a pH-adjusting method. The structure, morphology, surface area and pore size distribution of the samples were systematically characterized by using XRD, FT-IR, SEM, TEM and N 2 physical adsorption techniques. It was found that, when pH was adjusted to 7, the obtained sample still could exhibit hexagonal mesostructure, very similar to that of the pristine SBA-15 except for a slightly reduced long-range ordering and surface area. However, an increase in the unit cell and wall thickness of the samples suggested the more Ni species were incorporated into the framework of SBA-15. A further increase in pH to 9 produced deterioration of long-range ordering of the sample, possibly resulting from the blocking of some mesopores. Thus, the pH-adjusting method played an important role on the structure of Ni–SBA-15 composites. Measurements taken with increasing applied field revealed the samples having superparamagnetic behaviors. Furthermore, the saturation magnetization values were increased with the more Ni species transforming into magnetic nanoparticles by the increasing pH.
研究领域:
材料科学
·
化学工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2016
·Vol. 4
·期 27
·10609-10617
·
IF 8.262
Dewei Liang,Shouliang Wu,Jun Liu,Zhenfei Tian,Changhao Liang
Morphology control and impurity doping are two widely applied strategies to improve the electrochemical performance of nanomaterials. Herein, we report an environmentally friendly approach to obtain Co-doped Ni(OH)2 nanosheet networks using a laser-induced cobalt colloid as a doping precursor followed by an aging treatment in a hybrid medium of nickel ions. The shape and specific surface area of the doped Ni(OH)2 can be successfully adjusted by changing the concentration of sodium thiosulfate. Furthermore, a Co-doped Ni(OH)2 nanosheet network was further converted into Co-doped NiO with its pristine morphology retained via facile thermal decomposition in air. The structure and electrochemical performance of the as-prepared samples are investigated with scanning and transmission electron microscopy, energy dispersive X-ray analysis, X-ray diffraction, Fourier transform infrared spectroscopy, the nitrogen adsorption–desorption isotherm technique, and electrochemical measurements. The Co-doped Ni(OH)2 electrode shows an ultrahigh specific capacitance of 1421 F g−1 at a current density of 6 A g−1, and a good retention level of 76% after 1000 cycles, in sharp contrast with only a 47% retention level of the pure Ni(OH)2 electrode at the same current density. In addition, the Co-doped NiO electrode exhibits a capacitance of 720 F g−1 at 6 A g−1 and 92% retention after 1000 cycles, which is also superior to the corresponding values of relevant pure NiO electrodes. The Co2+ partially substitutes for Ni2+ in the metal hydroxide and oxide, resulting in an increase of free holes in the valence band, and, therefore, enhancement of the p-type conductivity of Ni(OH)2 and NiO. Moreover, such novel mesoporous nanosheet network structures are also able to enlarge the electrode–electrolyte contact area and shorten the path length for ion transport. The synergetic effect of these two results is responsible for the observed ultrahigh pseudocapacitor performance.
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
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2024
·
IF 3.7
Yutong Pan,Pengju Gao,Shixiong Tang,Xiaoyu Han,Ziwen Hao,Jiyi Chen,Zhenmei Zhang,Heng Zhang,Xiaohui Zi,Maoshuai Li,Shiwei Wang,Yue Wang,Xinbin Ma
This work synthesized a series of Ni/CeO 2 /Al 2 O 3 catalysts with varying CeO 2 doping amounts to enhance low-temperature CO 2 methanation. The introduction of CeO 2 weakens the interaction between Ni and Al 2 O 3 , leading to the formation of Ni-CeO 2 active sites. This results in a high dispersion of Ni and CeO 2 , improved catalyst reducibility, increased number of active sites, and enhanced the CO 2 methanation. This work further investigated the impact of WHSV and catalyst stacking configuration to enhance the reaction. When the catalyst is stacked into three segments with a temperature gradient of 330 °C, 300 °C, and 250 °C under WHSV=9000 ml·h –1 ·(g cat) –1 , the CO 2 conversion significantly increases to 95%, which is remarkably close to the thermodynamic equilibrium (96%).
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Yongqian Shen,Fan Zhang,Yuchen Zhang,Minmin Dang,Bin Li,Jiqiang Ma,Xueyan Du
Multifunctional microwave absorbers with robust hydrophobicity and enhanced wave absorption are of great significance for human health and the martial applications. Herein, carbon nanofibers (CNFs) inlaid with Ni/NiO and SiO 2 nanoparticles were prepared by electrospinning and in-situ annealing method. Contrast experiments at different annealing temperatures had been conducted to illustrate the formation process and microwave loss mechanism of Ni/NiO/SiO 2 /CNFs. At the annealing temperature of 550 °C, the optimal reflection loss (RL) of −40.1 dB was reached at 16.6 GHz with a thickness of 2.5 mm, the effective absorption bandwidth (EAB) was 5.2 GHz. The maximum EAB of 8.0 GHz was obtained as the thickness close to 3.0 mm, covering the half of X band and entire Ku band. It was worth mentioning that the introduction of nano SiO 2 into the Ni/NiO/CNFs annealed at 550 °C could refine the nanoparticles of Ni, promote the formation of Ni, improve the complex permittivity, and ultimately widen the EAB. Moreover, the contact angle (CA) of the Ni/NiO/SiO 2 /CNFs membranes annealed at 450, 550, 650 and 750 °C was 154.3°, 138.7°, 142.2° and 144.9°, respectively, illustrating that the products were of robust hydrophobicity. Therefore, the as-prepared NFs are promising in multifunction wave absorbers.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Chunmiao Liu,Yanchun Tong,Chang Liu,Meng Xu,Haibin Sun,Shigang Wu,Yujun Zhao,Jiao Li,Xue Guo,Yurun Feng
Faced with severe electromagnetic wave (EMW) pollution, the development of high-performance EMW absorbers remains a formidable challenge. In this study, SiBCN/Ni fibers containing uniformly dispersed Ni 2 Si nanoparticles were synthesized by electrospinning method with polymer-derived ceramics method, and their electromagnetic properties were evaluated. The low permeability threshold of the fibers ensures sufficient conduction loss effect. The in situ grown Ni 2 Si nanoparticles provide a magnetically coupled network, which is more conducive to obtaining excellent impedance matching. Furthermore, the presence of β-SiC, SiO 2 , and Si 2 N 2 O generates numerous heterogeneous interfaces (e.g., C-SiC and C-Ni 2 Si), leading to enhanced interfacial polarization through the accumulation of charges. As a result, the prepared SiBCN/Ni fibers exhibit impressive EMW absorption properties . At a Ni content of 1 wt%, the effective absorption band (EAB) is 4.32 GHz (13.68–18 GHz). At a Ni content of 1.5 wt%, the minimum reflection loss (RL min ) is −52.98 dB, and the sample has excellent radar scattering capabilities, which is verified by CST Microwave Studio simulations. Therefore, SiBCN/Ni fibers are promising as excellent EMW absorbing materials in practical applications.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
Energy Technology
·
2024
·
IF 3.6
Xueli Zhang,Shan Hu,Fangyuan Zhang,Shuchen Xing,Huilin Hu,Jinhua Ye,Defa Wang
As a promising technology to mitigate global carbon emissions, photothermal catalytic CO 2 reduction remains a great challenge in increasing the conversion efficiency and regulating the product selectivity. Herein, a series of phase-separated Ni–Mo alloy catalysts for efficient photothermal CO 2 reduction with tunable CO selectivity is reported. With the increase of Mo content, the evolution rate and selectivity of CO increases. The optimal catalyst Ni 1 Mo 1 achieves 32.1% CO 2 conversion with 98.0% of CO selectivity and 71.1 mmol g cat −1 h −1 of CO evolution rate under a 300 W xenon lamp irradiation. Further increasing the Mo content reduces the CO evolution rate while maintaining the high CO selectivity. In the mechanistic study, it is revealed that the Ni–Mo alloy with an appropriate Ni/Mo ratio (e.g., Ni 1 Mo 1 ) possesses a modified electronic structure with more negative d-band center, which increases the light absorption, reduces the H 2 dissociation, and favors the CO desorption, thereby leading to efficient and selective photothermal reduction of CO 2 to CO. In this work, a viable strategy to design nickel-based catalysts is provided for efficient and selective photothermal CO 2 reduction via composition-mediated modification of electronic structure.
研究领域:
材料科学
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环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Caihong Wang,Weiliang Qi,Ying Zhou,Wandi Kuang,Tamil Azhagan,Tiju Thomas,Chunjie Jiang,Siqi Liu,Minghui Yang
Efficient semiconductor-cocatalyst junctions are of direct relevance to solar energy based fuel generation. Here, Ni-Mo ternary nitrides based one-dimensional hierarchical structures (In 2 S 3 -Ni 0.2 Mo 0.8 N(Ni)) have been successfully prepared and used to achieve visible light driven H 2 evolution. Because of the metallic-like properties of the transition metal nitrides, Ni 0.2 Mo 0.8 N(Ni) as co-catalysts can promote photo-generated charge-carriers transportation/separation and decrease the overpotential of H 2 -evolution. Thus, the photocatalytic property of optimal 1 wt% In 2 S 3 -Ni 0.2 Mo 0.8 N(Ni) exhibits a hydrogen evolution rate of 614.2 μmol g -1 h −1 , which is about 10 times as high as that of blank In 2 S 3 (61.4 μmol g −1 h −1 ). Besides, the pure Ni 0.2 Mo 0.8 N shows higher co-catalytic properties than Ni 0.2 Mo 0.8 N(Ni). This indicates that the metallic Ni (and related species) lowers the co-catalytic role of ternary nitrides. Another robust indication of this is the fact that In 2 S 3 -Ni 0.2 Mo 0.8 N nanohybrid displays about 2 times higher H 2 evolution rate than In 2 S 3 -Ni 0.2 Mo 0.8 N(Ni).
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2017
·Vol. 122
·期 1
·525-538
·
IF 1.264
Li Xin,Meng Fanhui,Cheng Yang,Gao Yuan,Li Zhong
Mesoporous silica (SiO 2 ) supported highly dispersed Ni catalysts with ZrO 2 and surfactant β-cyclodextrin (CD) were prepared by the impregnation method, and their catalytic performance for three-phase methanation of CO were evaluated. It is shown that ZrO 2 promotes the dispersion of Ni species on mesoporous SiO 2 , leading to the increase in Ni dispersion and methanation activity. For the ZrO 2 content, the optimum is 5 wt%. Moreover, when adding CD in the preparation of Ni5Zr/SiO 2 catalyst, CD was found effectively enhanced the dispersion of Ni species and interaction between Ni species and support, leading to a smaller size of NiO particles and more exposed active surfaces, which promotes the CO adsorption capacity. As the molar ratio of CD/Ni rises, the crystallite size of metallic Ni decreased. Ni5Zr/SiO 2 (1:5) catalyst prepared with 5 wt% ZrO 2 and 1:5 molar ratio of CD/Ni shows the optimal catalytic activity for the three-phase CO methanation reaction. This is because of the highest dispersion of metallic Ni and smallest size of NiO particles.
研究领域:
化学工程
·
催化
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2024
·Vol. 154
·期 7
·3829-3838
·
IF 2.3
Wang Mingyue,Li Ting,Tian Yuhao,Zhang Jiarong,Cai Weijie
To develop high-performance catalysts for greenhouse gas CO 2 reforming with ethanol (EDR) is progressively inspired by the urgent requirement of CO 2 elimination in order to meet with the sustainable development. In this work, the bimetallic Co(Ni)/ZnO catalyst derived from MOFs was investigated in detail with a focus on the effect of Ni dopant. The EDR results indicated that the bimetallic Co(Ni)/ZnO catalyst presented better activity as well as less formation of byproducts in comparison with the monometallic Co/ZnO catalyst. 100% of ethanol conversion was obtained at 500 °C for Co(Ni)/ZnO versus 650 °C for Co/ZnO. Moreover, no acetone formation was observed over Co(Ni)/ZnO catalyst while the concentration of acetone in Co/ZnO was as high as 10 mol%. Characterization results depicted that the strong synergistic effect between Ni and Co in Co(Ni)/ZnO catalyst might greatly stabilize active metal cobalt with smaller particle size, improve the reducibility and facilitate the generation of oxygen defects, thereby enhancing the catalytic performance. To a certain extent, this work might contribute to the design of efficient catalysts for other catalytic applications. Graphical
研究领域:
催化
·
环境化学
·
材料科学
·
绿色化学
·
能量转换
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Mengyang Xu,Chao Sun,Xiaoxue Zhao,Haopeng Jiang,Huiqin Wang,Pengwei Huo
Fabricating the hierarchical heterostructure is efficient way for enhancing CO 2 conversion of semiconductor photocatalysts. Herein, a simple strategy has been employed to prepare several 3D hierarchical CdS/Ni-MOF heterostructure photocatalysts, and the selective photoreduction of CO 2 to CO under simulated sunlight in the gas–solid phase reactor. Among the prepared photocatalysts, 20%-CdS/Ni-MOF shows the best CO yield, which was 16 times and 7 times that of Ni-MOF and CdS, respectively. By controlling the morphology of the catalyst, we found that the significant improvement in photocatalytic activity can be ascribed to the synergistic effect of heterostructure in CdS/Ni-MOF and its unique hierarchical structure, which can improve the efficiency of charge transmission and provides abundant active sites, etc. Finally, the preliminary photocatalytic mechanism was discussed by in situ FTIR and liquid ultraviolet spectrophotometer.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
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