CHEMICAL ENGINEERING JOURNAL
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2020
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IF 10.652
Yajie Chen,Wei Ren,Zilong Zheng,Ganggang Wu,Bin Hu,Junhong Chen,Jiaxin Wang,Chunpei Yu,Kefeng Ma,Xinli Zhou,Wenchao Zhang
The development of nanothermites with adjustable reactivity has always been the research hotspot in the field of energetic materials, and its key issue is to control the interfacial contact extent and diffusion length between fuel and oxidizer. Here, the 3DOM CuO/Al, 3DOM CuO/Al-NPs and CuO-NPs/Al-NPs nanothermites, which show a gradual decrease in contact extents between reactants, were firstly prepared simultaneously using magnetron sputtering, P4VP self-assembly and ultrasonic mixing, respectively. The DSC thermograms show that the heat release of the 3DOM CuO/Al (sputtering 200 nm Al) can reach 2541.4 J/g, much larger than either value of the prepared 3DOM CuO/Al-NPs and CuO-NPs/Al-NPs. The activation energies of these CuO/Al systems also exhibit the similar results as the heat releases. However, the 3DOM CuO/Al-NPs can lead to the highest combustion pressure (24.6 MPa), the shortest pressure rise time (0.067 ms), and the fastest pressurization rate (647.98 GPa/s), followed orderly in corresponding values by the CuO-NPs/Al-NPs and 3DOM CuO/Al. All data indicate that the contact extent between CuO and Al plays a great effect on the overall reactivity, and their differences in structure and volume are responsible for the diverse combustion pressure performance. Furthermore, the presence of reaction voids between components can promote the O diffusion to enhance the continuous mass and heat transfer for an efficacious reaction. Hence, it is believed that similar methods can be used to improve the contact extent and diffusion length between fuels and oxidants so as to achieve an adjustment in reactivity for various nanothermites.
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
MICROPOROUS AND MESOPOROUS MATERIALS
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2023
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IF 5.2
Ne Ni,Xiuzhi Gao,Enhui Xing,Yuan Zhu,Jianqiang Liu,Mudi Xin,Ying Ouyang,Yibin Luo,Xingtian Shu
The promotional effects of phosphorous modification on ZSM-5 zeolites by phosphorus oxyacids (H 4 P 2 O 7 , H 3 PO 4 , H 3 PO 3 , and H 3 PO 2 ) with different molecular sizes were investigated with catalytic cracking of n -tetradecane as the probe reaction. It was verified that the diffusion of P precursor molecules into ZSM-5 channels was important to prevent aggregation of P species for better stabilization on tetra-coordinated framework aluminum . Meanwhile, the P–Al interaction was proposed based on results of 27 Al, 31 P, and 29 Si MAS NMR. With H 3 PO 2 as the P precursor, easy diffusion into ZSM-5 channels contributed to less formation of polyphosphates, homogeneous distribution of P species, better reserved crystallinity, microporous area and acidic sites for improving cracking performance of n -tetradecane.
研究领域:
化学工程
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催化
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材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CATALYSIS
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2022
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IF 8.047
Minjie Xu,Xianglin Liu,Guiyao Song,Yingying Cai,Bianfang Shi,Yitao Liu,Xiaoxu Ding,Zixu Yang,Pengfei Tian,Chenxi Cao,Jing Xu
Different iron species exhibit distinct activity and selectivity in CO 2 hydrogenation reaction. Herein, by controlling calcination temperature, Fe-Al interaction in Na promoted Fe-Al catalysts has been regulated, which further leads to various compositions of iron oxide (FeO x ) and iron carbides (Fe 7 C 3 and Fe 5 C 2 ) after CO activation and CO 2 hydrogenation reaction. The phase compositions and structures of Fe-Al catalysts are carefully distinguished by multiple characterizations, including XRD, XPS, MES and TEM, and the reactivity of different phases is studied with the combination of experiments (kinetics, TP and in situ DRIFTS) and Density Functional Theory (DFT) calculations. Our FeAl350 with the highest FeC x content shows the highest CO 2 conversion of 48.2% and the lowest CO selectivity of 10.1%, and FeAl900 with the highest Fe 5 C 2 / FeC x ratio presents the highest C 5+ selectivity of 44.6%. Finally, a correlation between different compositions of iron species with the activity and selectivity of Fe-based for CO 2 hydrogenation to olefins was established.
研究领域:
催化
·
化学工程
·
材料科学
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环境化学
✓ 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）