CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Qikui Man,Xueheng Zhuang,Zhenkuang Lei,Shiqi Zhu,Lining Pan,Yu Gao,Guoguo Tan
For obtaining the ecofriendly microwave absorbing composites, flake carbonyl iron was mixed to the flotation carbon waste of titanium slag by ball-milling processes. The composites of 4 h ball-milling present excellent microwave absorbing performance of minimum reflected loss (RL) of −54.9 dB at 7.8 GHz with thickness of 2.6 mm. The same composites provide the performance of RL < −10 dB with the thickness from 1.2 mm to 5 mm at corresponding matching frequency from 3.3 GHz to 18 GHz. It means that the absorbing peak can be tunable at the wide frequency range with only adjusting the thickness. The strong absorbing intensity and wide tunable frequency range are attributed to the proper impedance matching of dielectric property from flotation carbon waste of titanium slag and magnetic property from carbonyl iron. Also, this work provides a research approach for handling industrial waste which contains carbon.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
Nature Communications
·
2023
·Vol. 14
·期 1
·1-10
·
IF 16.6
Zhang Wenqing,Xi Dawei,Chen Yihong,Chen Aobo,Jiang Yawen,Liu Hengjie,Zhou Zeyu,Zhang Hui,Liu Zhi,Long Ran,Xiong Yujie
Oxidative carbonylation of methane is an appealing approach to the synthesis of acetic acid but is limited by the demand for additional reagents. Here, we report a direct synthesis of CH 3 COOH solely from CH 4 via photochemical conversion without additional reagents. This is made possible through the construction of the PdO/Pd–WO 3 heterointerface nanocomposite containing active sites for CH 4 activation and C–C coupling. In situ characterizations reveal that CH 4 is dissociated into methyl groups on Pd sites while oxygen from PdO is the responsible for carbonyl formation. The cascade reaction between the methyl and carbonyl groups generates an acetyl precursor which is subsequently converted to CH 3 COOH. Remarkably, a production rate of 1.5 mmol g Pd –1 h –1 and selectivity of 91.6% toward CH 3 COOH is achieved in a photochemical flow reactor. This work provides insights into intermediate control via material design, and opens an avenue to conversion of CH 4 to oxygenates.
研究领域:
化学工程
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光化学
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材料科学
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催化
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产品关联
DOI
PubMed
高影响因子
Nano Materials Science
·
2024
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IF 12.6
Weiwei Qi,Lan Xiang,Mingqiang Ning,Tao Liu,Yuanyuan Li,Xueheng Zhuang,Ganggang Lv,Qiang Wu,Guoguo Tan,Qingzheng Jiang,Qikui Man,Baogen Shen
With the increasing requirements of electromagnetic wave (EMW) absorption, developing EMW absorbers with high-efficiency anti-corrosion performance which can be effectively applied in extreme corrosive environments is imperative and constitutes a hot issue in the current research. Herein, based on the composition modulation of ZrO 2 and SiO 2 layer, the dual-oxides confined carbonyl iron (CI@ZrO 2 /SiO 2 ) composite displays a minimum reflection loss ( RL min ) of −48.58 [email protected] mm and an effective absorption bandwidth (EAB) of 7.62 [email protected] mm. Besides, the CI@ZrO 2 /SiO 2 displays superior corrosion resistance with corrosion current density ( i corr ) of 8.62 × 10 −7 A/cm 2 and polarization resistance ( R p ) of 3.64×10 5 Ω. This work proposes a strategy to optimize the broadband EMW absorption properties as well as the mass production toward the corrosion resistance applications.
研究领域:
材料科学
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电磁学
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腐蚀科学
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Ping Gong,Yan Li,Chenxing Xin,Qiaoyu Chen,Liang Hao,Qinglei Sun,Zheng Li
An effective method to fabricate barium titanate (BTO)/carbonyl iron powder (CIP) composites with enhanced microwave absorption (MA) performance was prepared via multimaterial digital optical processing (DLP) 3D printing technique. The bilayer-gradient honeycomb structural absorber (BGHSA) with adjustable broadband can be obtained by leveraging of varying compositional and structural design (layered thickness ratios , and gradient structures). The optimal reflection loss ( R L ) value and effective bandwidth of BGHSA can reach −51 dB and 15.4 GHz, respectively, exhibiting a distinct improvement ( R L increased by 32.4% and effective bandwidth by 42.9%) compared with the reference. The highly improved performances especially in the broadband absorption (15.4 GHz) were mainly attributed to the better impedance matching and waves multi-reflections. This work provides a promising strategy to fabricate functionally graded materials for potential application in the absorption of electromagnetic waves .
研究领域:
材料科学
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电磁学
✓ 已验证
DOI
高影响因子
Catalysts
·
2023
·Vol. 13
·期 10
·1327
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IF 3.9
Di Wang,Jiangang Lv
Methyl glycolate was synthesized as a precursor to ethylene glycol from the acid-catalyzed carbonylation of formaldehyde, followed by esterification with methanol. Homogeneous acids and different solid acids (e.g., resins and zeolites) were used as catalysts, and the effect of the solvent was examined. Afterward, a carboxylic acid protection strategy was proposed. With sulfolane and acetic acid as the mixed solvent, the solubility of CO increases, and the reaction rate can be accelerated. The rapid reaction between acetic acid and glycolic acid inhibits glycolic acid polymerization and pulls the reaction balance to promote the carbonylation reaction rate. Under the optimal solvent system (a molar ratio of acetic acid to sulfolane of 1:5) and the appropriate reaction conditions, the selectivity of the target product is higher than 85%. Solid acid catalysts with a −SO3H or −CF2SO3H functional group are supposed to be efficient in the carbonylation of formaldehyde, based on which a supported Nafion catalyst with a high surface area and total acid content was designed and synthesized. The novel supported Nafion catalyst presents a high total acid content and high Brönsted–Lewis acid ratio due to the characteristics of modified zeolite and, thus, leads to the high reactivity and very low selectivity of the by-product. A possible reaction mechanism is proposed to explain the product’s distribution by ascribing the formation of different products to different types of acid sites.Keywords:carbonylation;formaldehyde;methyl glycolate;ethylene glycol;acid catalyst
研究领域:
化学合成
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催化化学
✓ 已验证
DOI
高影响因子
CARBON
·
2020
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IF 8.821
Yuxin Zuo,Xinran Su,Xinwei Li,Zhengjun Yao,Tingting Yu,Jintang Zhou,Jing Li,Jiong Lu,Jun Ding
Impedance matching and enhanced microwave attenuation have been proven to be effective strategies for improving reflection loss (R L ) and widening of the effective absorption (R L < −10 dB) bandwidth of absorbers. Herein, we present novel multimaterial bilayer absorbing composites consisting of graphene/Li 0.35 Zn 0.3 Fe 2.35 O 4 /polymethyl methacrylate (GFP) as the matching layer and graphene/carbonyl iron powder/polymethyl methacrylate (GIP) as the absorption layer via our multimaterial digital light processing (DLP) 3D printing method. Through numerical calculations, microwave absorption performance of the bilayer absorber is found to be greatly enhanced as compared to its constituents. In addition, the effective absorption bandwidth can be also tuned via differing ratios of the GFP/GIP layer thicknesses under a fixed total thickness. A GFP/GIP bilayer of 1.4/2.6 mm was optimized based on R L . Experimented maximum R L peaks of −46.1 and −17.9 dB were revealed at frequencies of 4.7 and 15.7 GHz, respectively, with effective absorption bandwidth up to 3.5 GHz (4.15–5.35, 14.7–17.0 GHz). The microwave absorption performance of the GFP + GIP bilayer absorber is significantly improved by proper impedance matching and multiple-type loss forms. Overall this work provides a new strategy to manufacture efficient, broadband, and adjustable microwave absorbers by 3D printing .
研究领域:
材料科学
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电磁学
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制造技术
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2024
·
IF 7.1
Xiang Hui,Liguo Wang,Jianhui Shi,Tiping Wei,Fengqin Guo,Yan Cao,Peng He,Jiajun Zhang,Huiquan Li
The methoxycarbonylation of amines into carbamates via the construction of a C–N bond is an important reaction in pharmaceutical and fine chemical syntheses. However, the methoxycarbonylation of amines with dimethyl carbonate (DMC) without metal-based catalysts or other base catalysts has rarely been studied, and the reaction mechanisms remain underexplored. Herein, efficient methoxycarbonylation of biobased pentanediamine (PDA) with DMC promoted by water is proposed. The addition of water as a catalyst resulted in a 4-fold increase in yield. The conducted kinetic studies showed that proton transfer from PDA to methoxy occurs through the hydrogen bond between the zwitterionic intermediate and water. In situ analyses have shown that OH– and water form hydrogen bonds with the ether O atom of DMC and hydroxyl H atoms of PDA, synergistically promoting the elimination of the methoxy group. The addition of water reduced the energy barrier of the methoxy group elimination from 16.3 to 0.6 kcal/mol, confirming the results of theoretical computations. Furthermore, the methyl (5-aminophenyl)carbamate intermediate was recycled into dimethyl pentane-1,5-diyldicarbamate without the use of an additional catalyst, which was mediated by the hydrogen bond between PDA and methyl (5-aminophenyl)carbamate. The reported mild methoxycarbonylation of biobased PDA under metal-free conditions is a green and sustainable method of synthesizing biobased dicarbamate.
研究领域:
有机化学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-17
·
IF 14.7
Zheng Botuo,Zhong Liling,Wang Xiaoxiao,Lin Peiyao,Yang Zezhou,Bai Tianwen,Shen Hang,Zhang Huagui
Inverse vulcanization exploits S 8 to synthesize polysulfides. However, evolution of products and its mechanism during inverse vulcanization remains elusive. Herein, inverse vulcanization curves are obtained to describe the inverse vulcanization process in terms of three stages: induction, curing and over-cure. The typical curves exhibit a moduli increment before declining or plateauing, reflecting the process of polysulfide network formation and loosing depending on monomers. For aromatic alkenes, in the over-cure, the crosslinked polysulfide evolves significantly into a sparse network with accelerated relaxation, due to the degradation of alkenyl moieties into thiocarbonyls. The inverse vulcanization product of olefins degrades slowly with fluctuated relaxation time and modulus because of the generation of thiophene moieties, while the inverse vulcanization curve of dicyclopentadiene has a plateau following curing stage. Confirmed by calculations, the mechanisms reveal the alkenyl groups react spontaneously into thiocarbonyls or thiophenes via similar sulfur-substituted alkenyl intermediates but with different energy barriers.
研究领域:
材料科学
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化学
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产品关联
DOI
PubMed
高影响因子
Green Energy & Environment
·
2025
·
IF 14.6
Xiang Hui,Jianhui Shi,Jiajun Zhang,Yan Cao,Huiquan Li,Peng He,Liguo Wang
The carbonylation of amines offers a promising route for synthesizing N-substituted carbamates with high atom economy. However, conventional catalysts exhibit limited catalytic efficiency, and the underlying proton transfer mechanism remains elusive. Herein, we reported a metal-free, room-temperature strategy utilizing 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) as a dual hydrogen bond catalyst to synergistically activate propylamine (PA) and dimethyl carbonate (DMC). This green catalytic system achieves a 10-fold acceleration in reaction rate compared to other hydrogen bonding catalysts under mild conditions. This is enabled by dual hydrogen bonding of TBD with PA and DMC, which facilitates rapid proton transfer and stabilizes tetrahedral intermediates. Theoretical calculations confirm that the dual hydrogen bond system significantly lowers activation energy compared to single hydrogen bond analogs. Furthermore, it was revealed that the hydrogen bonding network within the product is the primary factor responsible for the sluggish reaction rate. This study demonstrates the effectiveness of a dual hydrogen bond system in accelerating the carbonylation of amines and provides a green route to access carbamates.
研究领域:
化学
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催化科学
·
有机合成
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Lei Zhu,Changyou Zhang,Qiwang Shao,Mengxuan Qin,Qing Li,Chao Peng,Chunchen Yuan,Donghong Wang,Chunyi Zhi
Due to their structural diversity, environmental friendliness, and resource renewability, organic electroactive compounds are versatile hosts for the energy storage of different metal ions. However, the consistency and variety of the energy storage performance and mechanism for the designed organic electrode materials in aqueous electrolytes toward different metal ions have rarely been researched. Here, one type of organic material integrated with anhydride and imide groups was designed and studied in detail. Among the two functional groups, the anhydride carbonyl groups were found to be the dominant contributors during the initial discharge step due to the higher binding energy toward the different metal ions, while the imides were responsible for the second-step coordination with monovalent metal ions. With the increment of the valence of guest metal ions, the activity of the imides decreased and became nearly inactive for the storage of aluminum ions. On the contrary, the anhydride carbonyl groups were always active for the storage of various metal ions and became the capacity contributors when the valence of the metal ions increased. Moreover, similar energy storage behaviors and close potentials were detected during the first discharge step for these different metal ions.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Bingning Wang,Yeshuang Wang,Zhen Wang,Song Yang,Chao Yang,Jiawei Kou,Huiling Fan,Ju Shangguan
In this study, we report a simple strategy to enhance the low-temperature catalytic performance of γ-Al 2 O 3 for carbonyl sulfide (COS) hydrolysis by regulating the dissociation of H 2 O. Specifically, tetrabutylphosphonium chloride (TBuPC), an ionic liquid, was introduced onto γ-Al 2 O 3 via ultrasonic impregnation. There was a strong interaction between Cl in TBuPC and Al sites in tetrahedral interstices of γ-Al 2 O 3 , and Al sites in octahedral interstices were acted as main adsorption sites of H 2 O. Additionally, the hydrogen bond Cl···H-O lowered the dissociation energy of H 2 O on Al sites in octahedral interstices of γ-Al 2 O 3 , leading to the generation of abundant basic –OH groups, which served as active sites for COS adsorption and hydrolysis. Consequently, 3TBuPC/γ-Al 2 O 3 achieved 100 % COS conversion at 60 °C, which was 2.05 times higher than that of γ-Al 2 O 3 . The catalytic mechanism of COS hydrolysis over 3TBuPC/γ-Al 2 O 3 involved the following steps: (1) H 2 O was adsorbed on the γ-Al 2 O 3 surface and dissociated, generating H* and basic –OH groups; (2) COS was adsorbed on the –OH sites, forming the intermediate HSCO 2 - ; (3) HSCO 2 - reacted with H* to release CO 2 and H 2 S. This significant enhancement provides a new insight for the design and development of low-temperature hydrolysis catalysts.
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
Journal of Zhejiang University-SCIENCE B
·
2019
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IF 1.879
Zhi-hao Tao,Chang Li,Xiao-fei Xu,Yuan-jiang Pan
Acrolein, known as one of the most common reactive carbonyl species, is a toxic small molecule affecting human health in daily life. This study is focused on the scavenging abilities and mechanism of ferulic acid and some other phenolic acids against acrolein. Among the 13 phenolic compounds investigated, ferulic acid was found to have the highest efficiency in scavenging acrolein under physiological conditions. Ferulic acid remained at (3.04±1.89)% and acrolein remained at (29.51±4.44)% after being incubated with each other for 24 h. The molecular mechanism of the detoxifying process was also studied. Detoxifying products, namely 2-methoxy-4-vinylphenol (product 21 ) and 5-(4-hydroxy-3-methoxyphenyl)pent-4-enal (product 22 ), were identified though nuclear magnetic resonance (NMR) and gas chromatography-mass spectrometry (GC-MS), after the scavenging process. Ferulic acid showed significant activity in scavenging acrolein under physiological conditions. This study indicates a new method for inhibiting damage from acrolein.
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）