PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2018
·Vol. 43
·期 7
·637-641
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IF 1.749
Naimeng Song,Jianchao Liu,Guoying Zhang,Zhenzhan Yan,Hongxu Gao,Li Yang
This paper describes the preparation of two combustion catalysts Tannin-Fe (Ta−Fe) and Phloroglucinol-Fe (Ph−Fe) by spray drying. The particle size and morphology of the particles are observed by scanning electron microscopy (SEM). The results of SEM image show that the particles are regular spherical and very good dispersion. The diameter of most spherical particles is about 1 μm. The effects of Ta−Fe and Ph−Fe on the thermal decomposition of RDX and AP were tested by differential scanning calorimeter (DSC). DSC dates show that Ta−Fe and Ph−Fe can advance the high temperature exothermic peak of AP 18.0 °C and 16.1 °C, respectively. The burning rates illustrates that both Ta−Fe and Ph−Fe can significantly increase the combustion rate of HTPB propellants. The formulation with 2 mass% Ta−Fe shows an average 21.31 % increase in burning rate and has a low value of the exponent n=0.48. The formulation with 2 mass%Ph−Fe has a burning rate 20 to 60 % larger than that of the initial AP/HTPB/Al formulation, and has a lowest exponent n=0.45.
研究领域:
材料科学
·
燃烧与推进
✓ 已验证
产品关联
DOI
高影响因子
Green Energy & Environment
·
2021
·
IF 8.207
Ruichang Xue,Mengwei Guo,Zhuoming Wei,Qibo Zhang
Ni–Fe bimetallic electrodes are currently recognized as a kind of benchmark transition metal-based oxygen evolution reaction (OER) electrocatalysts. Facile synthesis of Ni–Fe bimetallic electrode materials with excellent catalytic activity and satisfied stability by a simple and low-cost route is still a big challenge. Herein, well-defined Ni–Fe nanoparticles in-situ developed on a planar Fe substrate (Ni–Fe NPs/Fe) is fabricated via a facile one-step galvanic replacement reaction (GRR) carried out in an Ethaline-based deep eutectic solvent (DES). The prepared Ni–Fe NPs/Fe exhibits outstanding OER performance, which needs an overpotential of only 319 mV to drive a current density of 10 mA cm −2 , with a small Tafel slope of 41.2 mV dec −1 in 1.0 mol L −1 KOH, high mass activity (up to 319.78 A g −1 at an overpotential of 300 mV) and robust durability for 200 h. Impressively, the Ni–Fe bimetallic oxygen-evolution electrode obtained from the Ethaline-based DES is catalytically more active and durable than that of its counterpart derived from the 4.2 mol L −1 NaCl aqueous solution. The reason for this is mainly related to the different morphology and surface state of the Ni–Fe catalysts obtained from these different solvent environments, particularly for the differences in phy–chemical properties, active species formed and deposition kinetics, offered by the Ethaline-based DES.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Biomass Conversion and Biorefinery
·
2021
·Vol. 13
·期 9
·8115-8121
·
IF 4.987
Ren Dezhang,Jiang Xuelei,Zhang Nahui,Duo Jia,Norinaga Koyo,Huo Zhibao
Production of pyridine derivatives from bio-based feedstocks instead of fossil fuels is a promising strategy. The development of effective heterogeneous catalysts and mild reaction systems for pyridinization of renewable biomass derivatives remains a huge challenge. In this article, a direct and environment-friendly method was reported to produce 3-hydroxypyridine from bio-based furfural in water over a Raney Fe catalyst. Raney Fe exhibited an efficient catalytic performance for activation of the aldehyde group of furfural and afforded an 18.2% yield of 3-hydroxypyridine at 120 °C with ammonia as N source. The polymerization of furfural on the catalyst in hot water was the main cause of deactivation, which was verified by the scanning electron microscope (SEM), X-ray diffraction (XRD), and N 2 adsorption and desorption analysis. A possible mechanism for this reaction was also proposed. This study provides a new way for academia and industry to realize the synthesis of nitrogen-containing chemicals from biomass and its derivatives.
研究领域:
催化化学
·
绿色化学
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可再生资源转化
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2024
·
IF 9.7
Zhengshuai Sun,Rujiao Jiang,Wenbin Hua,Qi Wei,Qiaoxia Yuan,Baojun Yi
Biomass-based graphitic carbon is a promising material, but the effect mechanism of inherent alkali metals on the catalytic pyrolysis of biomass is still unclear. In this study, cellulose was selected as the model substance, and the influence mechanism of Na on the graphitization of cellulose catalytic pyrolysis was investigated through a combination of experiments and theoretical calculations. The results indicate that Na can interact with the carbon skeleton through van der Waals forces, thereby altering the spatial structure of graphite crystals and increasing the interlayer spacing of graphite by 27.7%. In addition, Na can coexist with Fe(III) in the form of oxides, while also increasing the reaction energy barrier of reverse hydroxylation and dehydration cyclization, decreasing the generation of reducing gases mainly composed of CO. This impedes the reduction of iron-based catalysts, thereby affecting the formation of the graphite microcrystalline structure. The research indicates that maintaining the ratio of Na content to iron-based catalysts within a 1:1 range is optimal for producing graphite carbon from cellulose.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2024
·
IF 5.6
Weijuan Lan,Yunlong Zhou,Jiaxin Liu,Yingxian Wang,Xin Jin,Dongxue Yin,Jiangtao Ji,Gaixiu Yang,Huan Zhang
Biomass carbon materials have attracted attention in various fields due to their excellent properties. In this study, CH 4 derived from biomass pyrolysis was utilized as a carbon source gas to synthesize carbon materials by chemical vapor deposition (CVD) in a two-stage reactor with purification system, with Fe 3+ -loaded nickel foam as the substrate under an argon atmosphere, using a self-designed experimental platform. The reaction process was optimized by examining the effects of the catalyst type, reaction temperature, reaction time, and gas flow rate on the structure and morphology of the carbon materials. The optimal preparation condition was to use FeCl 3 ethanol solution as catalyst, with CH 4 flow rate of 50 ml/min at 1000 °C for 25 min. The high quality carbon materials with uniform diameters (250–500 nm) were obtained on nickel foam substrate. The carbon materials obtained under optimal conditions were characterized and analyzed to investigate their excellent properties. Surface morphology and structure of as-formed carbon materials were characterized by SEM. The analysis of the XRD spectra and the Raman spectroscopy showed that the graphite diffraction peak (002) at 26.6°, the calculated intensity ratios for I D / I G and I 2D / I G were 0.257 and 0.545, respectively, indicated high degree of graphitization and purity of the carbon materials. Furthermore, the growth mechanism of carbon materials on the nickel foam substrate was discussed.
研究领域:
材料科学
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能源工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2023
·
IF 22.1
Lingxiang Huang,Yue Ma,Mufan Niu,Shenyong Ren,Qiaoxia Guo,Chunming Xu,Baojian Shen
Dry reforming reaction of greenhouse gas CH 4 and CO 2 was studied over Ni-Fe bimetallic catalyst, in which the composite support of C12A7-O 2- in MCM-41 was used. The isotope 13 CH 4 /D 2 O tracing experiment showed CO mainly comes from 13 CHx oxidation reaction and DH comes from CHx and D 2 O reaction, exhibiting lattice oxygen promotes CH X oxidation and water accelerate methane conversion. XPS and TPSR-MS studies exhibited the existence of lattice oxygen in catalysts produces a little H 2 O to facilitate a lower starting point at the reaction temperature. On-line MS investigation found that the trace water addition in the system accelerated the adsorption of CO 2 on support and promoted methane dissociation, the H 2 signal appears later than CO, indicating the oxidation reaction of CHx occurs after the dissociation of CO 2 . Besides, TG analysis tells us the H 2 O may consume Cα on the catalyst in time during the reaction process to remove carbon deposition.
研究领域:
化学工程
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2025
·
IF 7.3
Meng Xia,Longqi Li,Xiaocong Wang,Kaihao Xu,Shuai Zhang,Chengxue Zhang
During CO2/HCO3– reduction with renewable biomass, achieving high-efficiency production of the target products is vital but challenging. In this study, an NH2– functional-group-modified MIL-53(Fe) catalyst was synthesized using a facile and efficient method. Under the action of the NH2-MIL-53(Fe) catalyst, a clear synergistic effect was exhibited on the transformation of glucose and NaHCO3 into formic acid with a high yield of 50% at a low reaction temperature (190 °C) via a three-pronged route, which mainly involved the decomposition of intermediates of glucose to gradually reduce NaHCO3 to formic acid under hydrothermal conditions. An in-depth analysis of the catalytic mechanism and density functional theory calculations demonstrated that the increased alkalinity of active sites by the NH2– functional group incorporation into the catalytic system enhanced the crucial reaction steps and reduced the activation energy of the crucial reactions, including glucose isomerization, aldehyde intermediate retro-aldol condensation, and redox of aldehyde compounds and NaHCO3 to formic acid, thereby promoting the generation of target products and suppressing side products. This study addresses the challenge of reducing NaHCO3 from renewable biomass to commercial formic acid by constructing multifunctional active sites, thus providing a new strategy for achieving carbon cycling.
研究领域:
化学工程
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催化科学
·
可再生资源转化
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 11
·期 29
·15717-15723
·
IF 11.9
Jia-Wei Zhao,Kaihang Yue,Zi-Xiao Shi,Shu-Yin Wei,Wei-Qian Liang,Gao-Ren Li
In situ spectroscopic characterization has been considered as a key method to study catalytic mechanisms. However, most in situ spectroscopic characterizations can only be used to obtain the overall structure of the catalyst, and its spectral intensity depends on the average information about the catalyst as a whole or in a single area, which makes it difficult to determine the real active site of the catalyst. Herein, to overcome the limitations of traditional in situ spectroscopic characterizations, we developed in situ Raman mapping technology to achieve accurate characterizations of active sites during the oxygen evolution reaction (OER), and this work can directly identify and visualize the real active sites of Ni–Fe catalysts for the OER. The in situ Raman mapping technology clearly shows the surface reconstruction process and dynamic active site of the Ni–Fe catalyst during the OER, namely, Ni is converted to NiOOH and the formed NiOOH/Fe–NiOOH as an active site catalyzes the OER. The visualization of the dynamic active site developed in this paper will promote the understanding of the OER catalytic process and can be used in other homo/heterogeneous catalysis fields.
研究领域:
催化化学
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材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2023
·
IF 9.2
Haiyang Lan,Jiaming Chu,Xingyu Chen,Qi Zhou,Weitao Jin,Yanhong Zhang,Juan Zhou
In a direct ammonia proton ceramic fuel cell (DA-PCFC), attaching a catalyst layer on the surface of the ammonia electrode is known to optimize the cell's electrochemical performance and long-term stability. In this study, the Fe catalyst layer is added to the ammonia electrode of the full cell which is prepared with the structure Ni– BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ (BZCYYb) (support layer)|Ni-BZCYYb (active layer)|BZCYYb|La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ to investigate its impact on the electrochemical performance and stability of the electrode. Under the conditions of 700 °C and 20 ml min −1 ammonia fuel, the peak power densities of cells with and without the Fe layer reach 585.051 and 463.671 mW cm −2 , respectively. It is evident that the addition of the Fe catalytic layer significantly improves the electrochemical performance of the cell. Stability tests are carried out for cells with and without the Fe layer at 650 °C, 0.36 A cm −2 , and 0.32 A cm −2 constant current discharge. After discharge for 313 and 372 h, both cells show good stability, and the discharge curves of the two cells are consistent after 100 h. The high M − N binding energy of the Fe catalytic layer improved the initial performance of the cell, but this improvement is not sustained over the stability.
研究领域:
材料科学
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2024
·
IF 4.4
Haixiang Shi,Yiyuan Xu,Tongming Su,Xuan Luo,Xinling Xie,Zuzeng Qin,Hongbing Ji
The surface acidity and structure of catalysts play crucial roles in cinnamaldehyde (CAL) selective hydrogenation to manufacture cinnamyl alcohol (COL). Herein, a Co–Fe-supported acidified bentonite catalyst (Co–Fe/ACBT) was prepared via sulfuric acid treatment of bentonite (BT) and the traditional impregnation method. The combination study, including FT-IR spectra of adsorbed pyridine and ammonia temperature-programmed desorption (NH3-TPD), showed that Co–Fe/ACBT has vast acidic sites mainly originating from surface unsaturated metal sites of ACBT, which prefer to adsorb polar >CO but not nonpolar >CC<. X-ray photoelectron spectroscopy (XPS) verified that the effect of electron transfer was significantly enhanced when the active metal was loaded on ACBT, leading to an increase in the electron cloud density of the Co species, which promoted the activation of >CO. Due to the modified electronic properties of Co species and abundant acidic sites, Co–Fe/ACBT exhibited a 90.5% conversion and 86.8% hydrogenation selectivity from CAL to COL, which are notably greater than those of the Co–Fe-supported bentonite catalyst (32.0% CAL conversion and 66.4% COL selectivity).
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2021
·Vol. 23
·期 8
·4690-4699
·
IF 3.676
Zhengyan Zhao,Wei Liu,Yantao Shi,Heming Zhang,Xuedan Song,Wenzhe Shang,Ce Hao
We report a combination of experimental and computational mechanistic studies for the photoreduction of CO2 to CO with water, catalyzed by single-atom Fe supported on graphitic carbon nitride (g-C3N4). Density functional theory (DFT) and time-dependent DFT (TDDFT) methods were utilized to explore the behavior of single-atom Fe in g-C3N4, which is of vital importance to the understanding of the CO2 reduction reaction (CO2RR) mechanism. The calculation results reveal that the rate-limiting step of the hydrogen-bonded complex in the absence of Fe atoms is the cleavage of C–O bonds in COOH radicals during the whole CO2RR, which includes the photophysical and photochemical processes. The presence of Fe atoms not only activated CO2 in the ground state and increased the rate constant of the limiting step in the photophysical process, but also functioned as the catalytic active center, lowering the reaction barrier of the C–O bond cleavage in COOH˙ in the photochemical process and resulting in improved photocatalytic activity. In addition, DFT calculations further demonstrated that the electron and proton transfer involved in the photophysical and photochemical processes is closely related to and induced by the hydrogen bonds in the excited state.
研究领域:
材料科学
·
催化化学
·
环境科学
✓ 已验证
DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2017
·Vol. 11
·期 4
·613-623
·
IF 1.712
Tang Honggui,Li Shuangshuang,Gong Dandan,Guan Yi,Liu Yuan
Carbon deposition and sintering of active components such as nano particles are great challenges for Ni-based catalysts for CO methanation to generate synthetic natural gas from syngas. Facing the challenges, bimetallic catalysts with different Fe content derived from layered double hydroxide containing Ni, Fe, Mg, Al elements were prepared by co-precipitation method. Nanoparticles of Ni-Fe alloy were supported on mixed oxides of aluminium and magnesium after calcination and reduction. The catalysts were characterized by Brunner-Emmett-Teller (BET), X-ray diffraction, hydrogen temperature programmed reduction, inductively coupled plasma, X-ray photoelectron spectroscopy, transmission electron microscopy and thermogravimetric techniques, and their catalytic activity for CO methanation was investigated. The results show that the Ni-Fe alloy catalysts exhibit better catalytic performance than monometallic catalysts except for the Ni4Fe-red catalyst. The Ni2Fe-red catalyst shows the highest CO conversion (100% at 260–350 °C), as well as the highest CH 4 selectivity (over 95% at 280–350 °C), owing to the formation of Ni-Fe alloy. In stability test, the Ni2Fe-red catalyst exhibits great improvement in both anti-sintering and resistance to carbon formation compared with the Ni0Fe-red catalyst. The strong interaction between Ni and Fe element in alloy and surface distribution of Fe element not only inhibits the sintering of nanoparticles but restrains the formation of Ni clusters.
研究领域:
催化化学
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材料科学
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能源化学
✓ 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）