JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
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2017
·Vol. 129
·期 3
·1875-1885
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IF 1.953
Cheng Jian,Zheng Yu,Li Zhenming,Liu Zuliang,Li Lixia,Zhao Fengqi,Xu Siyu
Abstract The purpose of this work was to study the catalytic reaction and its mechanism of ammonium perchlorate (AP) with cobalt complex of 2,6-diamino-3,5-dinitropyrazine-1-oxide (Co-LLM-105) during thermal decomposition process. At first, the catalytic performance of Co-LLM-105 on the thermal decomposition of AP was investigated by TG–DSC, TG-FTIR, non-isothermal kinetic and α – T kinetic curves analyses. Secondly, the thermal decomposition mechanism of Co-LLM-105 in the absence and presence of AP was proposed based on TG, DTG, DSC and thermolysis/RSFTIR analyses. The results showed that Co-LLM-105 exhibited excellent catalytic activity on the thermal decomposition of AP. Meanwhile, AP also exhibited some catalytic effects on the thermal decomposition of Co-LLM-105. Both of the components had catalytic effects on each other during the process. The formation of active CoCO 3 , Co 3 O 4 , CoO and Co(NH 3 ) 6 (ClO 4 ) 2 in situ in the system accounted for the higher catalytic activity of Co-LLM-105 for the thermal decomposition of AP was deduced. Graphical Abstract Co-LLM-105 exhibited excellent catalytic activity on the thermal decomposition of AP. Meanwhile, AP also exhibited some catalytic effects on the thermal decomposition of Co-LLM-105. Both of the components had catalytic effects on each other during the process.
研究领域:
化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Feng Xu,Hongge Yan,Jihua Chen,Zhengfu Zhang,Changling Fan
This work is focused on the mechanism study of nanoscale Co 3 O 4 powders prepared by an enhanced solid-state reaction method. The as-prepared powders are characterized by thermogravimetric-differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) with the powders ball milled for different times as the control. The results show that ball milling can accelerate the thermal decomposition process by approximately 18.2%. Moreover, the apparent thermal decomposition activation energy of CoCO 3 powders pretreated by the enhanced solid-state method declined by 33.2%. To elucidate this,the thermal decomposition kinetic equations of CoCO 3 powders, with and without ball milling, are calculated. And the thermal decomposition kinetic equation of the ball-milled powders is d α /d t = (2.42E6~2.19E7) exp [(8.74E3~9.96E3)/ T ] 4/3(1- α ) [-ln(1- α )] 1/4 ; while that of the powders lack of ball milling is d α /d t = (1.08E10–1.07E11) exp [(1.43E4~1.51E4)/ T ] 2/3 α −1/2 , respectively. The reaction process at different time points can be forecasted by the obtained equations.
研究领域:
材料科学
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化学工程
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物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2019
·Vol. 54
·期 22
·13914-13937
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IF 3.442
Pudukudy Manoj,Jia Qingming
A controlled acidic precipitation is reported for the direct synthesis of nanosheets self-assembled hierarchical tungstic acid microspheres, and their annealing-dependent thermal conversion into WO 3 microstructures is studied for the first time. The synthesis was carried out without the use of any structure directing agents and hydrothermal conditions. The microspheres were found to be consisting of many single-crystalline and highly oriented nanosheets that were hierarchically self-aggregated in spherical form for the minimization of surface energy. An experimentally validated time-dependent formation and growth mechanism was proposed for the development of microspheres. The characterization results indicated that the morphology-preserved thermal decomposition of H 2 WO 4 into WO 3 microspheres occurred at 400 °C, whereas a morphology distortion was noticed for the sample synthesized at 600 °C. The increase in annealing temperature further increased the crystallinity of WO 3 without changing its monoclinic crystal structure. However, it has a diminishing effect in the specific surface area, pore size and pore volume of the annealed samples. Moreover, the adsorption of methylene blue in aqueous medium was carried out to evaluate its potential environmental application. The WO 3 microspheres synthesized at 400 °C showed high adsorption capacity (63 mg/g) compared to the same at 600 °C (56 mg/g). The high activity could be ascribed to the synergistic effects of high surface area, low particle size, porosity, specific morphology and more negative zeta potential. The adsorption further followed pseudo-second-order kinetics with a best fit of the experimental and theoretical values.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2019
·Vol. 45
·期 3
·463-471
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IF 1.634
Ming Zhang,Fengqi Zhao,Yanjing Yang,Ting An,Wengang Qu,Hui Li,Jiankan Zhang,Na Li
Three kinds of ferrates (NiFe 2 O 4 , ZnFe 2 O 4 and CoFe 2 O 4 ) were prepared via the facile solvothermal method and characterized using SEM, TEM, XRD, XPS, FT-IR and BET instruments. The NiFe 2 O 4 , CoFe 2 O 4 and ZnFe 2 O 4 particles possess hollow structure with average particle size of 70, 220 and 360 nm, respectively. The catalytic performance of the ferrates for AP thermal decomposition were studied using DSC and TG-DTG methods, and the decomposition mechanism of AP were suggested. The catalytic effects of different ferrates for AP thermal decomposition were significantly different. The CoFe 2 O 4 has the best catalytic activity, and the high thermal decomposition peak temperature ( T HDP ) and apparent activation energy ( E a ) of AP were decreased by 108.99 °C and 37.38 kJ mol −1 in the presence of CoFe 2 O 4 sample. Adding ferrates has no obvious influence on the gas-phase decomposition products of AP, but has a great influence on the energy barrier of high temperature decomposition of AP. The excellent catalytic activity of CoFe 2 O 4 is mainly attributed to the synergistic interaction between Fe and Co, which is conducive to the thermal decomposition of AP.
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
Journal of Energy Chemistry
·
2024
·
IF 14
Shuzhe Yang,Hao Luo,Yukun Li,Qingqing Gao,Hui Li,Hongwei Cai,Xiaodan Li,Yanfen Wen,Yujin Tong,Tiefeng Liu,Mi Lu
Traditional pyrometallurgy and hydrometallurgy processes primarily focus on the recovery of valuable metals (Co, Ni, etc.) from spent lithium-ion batteries. However, these methods are not economical for recycling cheap LiFePO 4 . Herein, a synergistic thermal-decomposition and electric-drive strategy is proposed to recover the whole spent LiFePO 4 electrode by in-situ recovering the inactive lithium (dead lithium and trapped interlayer lithium). Firstly, the organic components in the dense solid electrolyte interface (SEI) are effectively decomposed through thermal-decomposition processing, exposing the dead lithium encapsulated within the SEI and recovering the electron channels between the dead lithium and graphite. Leveraging the difference between the Gibbs free energy of the dead lithium and graphite as the driving force facilitates the dead lithium inserting into the anode. Then, fully utilizing the remaining discharge capacity of the spent LiFePO 4 cell, the inactive lithium is reinserted into LiFePO 4 lattice during the electric-drive process. Consequently, the reactivated lithium content increases by more than 16%, reaching a capacity of 134.2 mA h g −1 compared to 115.2 mA h g −1 from degraded LiFePO 4 , allowing for effective participation in the subsequent cycling. This work provides new perspectives on highly profitable cycles with low energy and material consumption and a low carbon footprint.
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
JOURNAL OF SOLID STATE CHEMISTRY
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2022
·
IF 3.656
Tao Zhang,Qinggang Li
NH 4 VO 3 is an important vanadium source for the preparation of VO 2 . In the previous studies, the extra gas or solid reagents consumption is necessary for the preparation of VO 2 by using NH 4 VO 3 as vanadium source. The current work proposed a facile way for the fabrication of VO 2 (M) by the thermolysis of NH 4 VO 3 under the sealed atmosphere without extra gas or solid reagents consumption. The VO 2 (M) could be successfully synthesized by two step—thermolysis of NH 4 VO 3 at 400 °C under the sealed condition and heat treatment of VO 2 (B) at 500 °C under the N 2 condition. The dosage of NH 4 VO 3 and decomposition temperature had significant influences on the thermolysis process under the sealed condition. The NH 3 produced by the thermolysis provided a protective atmosphere that prevented the oxidization of VO 2 (B) by residual O 2 in the sealed reactor. Furthermore, the VO 2 (M) could be prepared directly under the sealed atmosphere by increasing reaction temperature to 700 °C. In this process, NH 4 VO 3 underwent a phase transition as the follows: NH 4 VO 3 →ammonium vanadium bronze→VO 2 (B)→VO 2 (M). The directly synthesized VO 2 (M) at 700 °C by the thermolysis of NH 4 VO 3 under the sealed condition showed great environmental stability and phase transition performance.
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
Molecular Catalysis
·
2023
·
IF 4.6
Tiantian Zhang,Jiacheng Xu,Yan Sun,Shiyu Fang,Zuliang Wu,Erhao Gao,Jiali Zhu,Wei Wang,Lianxin Dai,Weihua Liu,Buhe Zhang,Junwei Zhang,Shuiliang Yao,Jing Li
Nano-Au has a good catalytic activity for CO oxidation, but its catalytic mechanism is still not clear. Here, CO oxidation on Au 2 O 3 and its thermal decomposition products were studied using thermogravimetric-mass spectrometry (TG-MS) and operando diffuse reflectance infrared Fourier transform spectroscopy-mass spectrometry (DRIFTS-MS) to explore the key active components of Au catalyst for CO oxidation. The TG-MS results showed that Au 2 O 3 decomposed to AuO at 210 °C and Au at 375 °C and was oxidized to form Au oxide above 375 °C. When Au 2 O 3 decomposed into Au x O y (x>y) above 210 °C, the CO oxidation activity obviously increased. Au atoms in the Au-Au system serve as electron donor and CO adsorption sites. Au atom is oxidized to AuO by the O atom from O 2 decomposition following the Epling-Xu decomposition mechanism. A schematic diagram of the key components of Au 2 O 3 catalysts during CO oxidation was proposed based on TG-MS and operando DRIFTS-MS analysis results.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2023
·Vol. 52
·期 48
·18380-18390
·
IF 4
Yujie Yan,Bo Jin,Rufang Peng
The assembly of 2D Ti3C2Tx nanosheets into 3D structures with orderable structure has great importance for their use as catalyst carriers. However, Ti3C2Tx nanosheets are prone to accumulate in aqueous solutions owing to the strong van der Waals forces between Ti3C2Tx nanosheet layers, degrading their chemical properties. Carbon aerogel (Ti3C2Tx/G/Co) with a 3D porous structure and cobalt as the active site was prepared by a simple co-assembly–freeze–drying–high-temperature carbonization method for application in catalysis of ammonium perchlorate.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Ping Ye,Heng Ding,Bo Yang,Weimiao Wang,Xiaodong Li,Zhiqiang Qiao,Rui Li,Guangcheng Yang,Guoqing Lv
The ignition strategy of energetic materials using low-energy near-infrared (NIR) laser has garnered significant attention due to its enhanced safety and reliability. This study explores the use of a relatively photosensitive but mechanical insensitive energetic material, DATNBI, to facilitate the self-assembly of nano-CL-20 crystals into polycrystalline particles though solvothermal induction, yielding a rough structure conducive to NIR laser ignition. The findings demonstrate that by adjusting the content of DATNBI, it is possible to achieve micro-nano controllable spherical CL-20/DATNBI (C/D) particles, with CL-20 as the primary component and DATNBI as the auxiliary component. The incorporation of DATNBI and the rough surface structure enhance the light absorption of C/D particles in the NIR band. Additionally, the unique synergistic effect between CL-20 and DATNBI during thermal decomposition further promotes NIR laser ignition. As expected, the C/D particles achieved self-sustained combustion and exhibited excellent combustion performance under a 1064 nm laser, which is challenging to be achieved with raw CL-20 or raw DATNBI. Furthermore, the relatively insensitive DATNBI and spherical structure reduced the impact sensitivity of the C/D particles. This multifunctional material strategy, integrating energy, safety, environment-friendliness, and laser ignition performance, offers a novel approach for laser ignition of energetic materials.
研究领域:
化学
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材料科学
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能源与燃料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LOSS PREVENTION IN THE PROCESS INDUSTRIES
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2024
·
IF 3.6
Chenyang Pu,Zhi Wang,Boren Zheng,Bin Zhang
1,2,4-Triazole is a common intermediate used in the synthesis of pesticides and medicine, and has a very wide range of applications. As a kind of polynitrogen heterocycles, 1,2,4-triazole will release a lot of heat during thermal decomposition. If there is no comprehensive understanding of its pyrolysis behavior, there will be a very large thermal safety risk in the process involving 1,2,4-triazole in industrial production. At the same time, the instability of the substance may be affected by the presence of impurities, and the existing research on this aspect is quite scarce. Therefore, it is very necessary to study the effect of adding other substances on the thermal decomposition of 1,2, 4-triazole. The thermal decomposition characteristics and thermal runaway behavior of 1,2, 4-triazoles were revealed by thermodynamic experiments and various kinetic theoretical methods. According to the risk matrix, the thermal runaway danger level of 1,2, 4-triazole was determined to be level Ⅲ, which was an unacceptable risk. The results show that 1,2, 4-triazole has a huge heat release and the effect of thermal runaway is serious. In this study, three substances involved in the industrial production of fluconazole and flutriafol mixed with 1,2, 4-triazole were selected to explore their influence on the thermal decomposition of 1,2, 4-triazole under non-working conditions. DSC and ARC experiments consistently showed that these three impurities could reduce the reaction heat release of 1,2, 4-triazole to varying degrees, and confirmed that these three impurities could reduce the risk of thermal runaway of 1,2, 4-triazole to varying degrees. Among them, sodium hydride has the most outstanding performance, both in terms of reducing reaction heat release and reducing adiabatic temperature rise. The results can provide reference for loss control of 1,2,4-triazole in industrial applications.
研究领域:
化学工程
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热力学
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安全科学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Wenhao Deng,Yuehua Deng,Wang Zhao,Rui Zhang,Yanbin Jiang
Tetramethylammonium hydroxide pentahydrate (TMAH·5H 2 O) is easily decomposed when heated, which results in the difficulty of dehydration. In this study, a new process for dehydration of a TMAH propylene glycol solution using wiped-film molecular distillation was developed. The experiments were carried out to evaluate the effect of operating conditions on the performance of the dehydration with the operating temperature ranging from 65 °C to 90 °C, the operating pressure from 100 Pa to 2000 Pa and the mass flow rate from 36 to 162 g/min. The experimental results indicated that molecular distillation was capable of dehydrating TMAH solution to a water content of 0.65% from 5.82%. Then a modified Flash module in Aspen plus, which used the fitting factor and linear correlation between the simulated and experimental temperatures, was developed to simulate the dehydration process. The relative error between the modified simulated and experimental data is less than 5%, and the response surface methodology analysis was conducted to optimize the operating conditions. The optimal dehydration conditions were 85 °C, 100 Pa and 54 g/min feed flow rate, where the minimum water content in distilled solution is 0.43%. The results show that the process developed realizes a high efficiency of dehydration and prevents TMAH from thermal decomposition.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2023
·
IF 3.8
Zhen Zhang,Zhao Qin,Ming Zhang,Yifan Jiang,Chao Chen,Jiankan Zhang,Fengqi Zhao
The carbon dots (CDs) were prepared by the oxidation etching method. On this basis, the composite materials of CDs and Cu (CDs/Cu) were synthesized by the hydrothermal method . The elemental composition, morphology and structure were analyzed by TEM, SEM, EDS , XRD and XPS . The effects of CDs and CDs/Cu for thermal decomposition of TKX-50 pyrolysis were studied by DSC-FTIR-MS and in-situ solid FTIR . The CDs and CDs/Cu reduced the low-temperature decomposition peak temperature of TKX-50 by 10.1 ℃ and 16.1 ℃ respectively (10 ℃·min −1 ), and the second decomposition peak almost disappeared. This is because CDs and CDs/Cu can effectively facilitate the thermal decomposition of TKX-50 into NH 2 OH and 1,1′-ditetrazole diol (BTO). The CDs can promote the direct decomposition of BTO into small molecule gases and stable polymers at the initial pyrolysis stage. And they inhibit the combination of BTO and NH 3 into 5,5′-bistetrazole-1,1′-didiolate (ABTOX), which is more difficult to decompose. So, the HCN and N 2 /CO were increased obviously during pyrolysis while NH 3 and H 2 O content were decreased. On the other hand, the CDs/Cu promotes the decomposition of NH 2 OH in the first reaction. It manifested as the increase of NH 3 and H 2 O. At the same time, the CDs/Cu facilitates the transition of difficult to decompose ABTOX losing NH 3 to BOX to accelerate thermal decomposition reaction , playing a synergistic catalytic effect. Thus, in-situ solid FTIR signal of ABTOX was significantly weakened and the total content of NH 3 was raised, especially the significant expansion of NH 3 in the second stage. Finally, the influence of the catalysts in ignition characteristics was contrasted and discussed. Under the lower-power density region, the CDs and CDs/Cu decreased the ignition delay time of TKX-50. The CDs/Cu caused the flame propagation velocity of TKX-50 faster. Therefore, the CDs and their composites, as another new lightweight carbon material, are expected to be applied in the catalytic combustion of energetic materials.
研究领域:
材料科学
·
化学工程
✓ 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）