Catalysts
·
2024
·Vol. 14
·期 1
·36
·
IF 3.8
Min Zheng,Xiangzhou Li,Dulin Yin,Steven R. Kirk,Hui Li,Peng Zhou,Yanhong Yang
Carveol is a rare fine chemical with specific biological activities and functions in nature. The artificial synthesis of carveol from plentiful and cheap turpentine is expected to further improve development of pharmaceutical and industrial applications. A new green catalytic system for the preparation of high-value carveol from α-epoxypinane is presented. A novel ammonium salt solid acid (AC-COIMI-NH4PW) was obtained from phosphotungstic acid bonded with imidazole basic site on nitrogen-doped activated carbon which, after ammonia fumigation, presented an excellent catalytic performance for the selective rearrangement of α-epoxypinane to carveol in DMF as solvent under mild reaction conditions. At 90 °C for 2 h, the conversion of α-epoxypinane could reach 98.9% and the selectivity of carveol was 50.6%. The acidic catalytic sites exhibited superior durability and the catalytic performance can be restored by supplementing the lost catalyst. Based on the investigation of catalytic processes, a parallel catalytic mechanism for the main product was proposed from the rearrangement of α-epoxypinane on AC-COIMI-NH4PW.
研究领域:
化学工程
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材料科学
·
有机合成
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·
IF 2.7
Yucheng Zi,Dong Chen,Guochen Wang,Yuhong Ma,Wantai Yang
A simple strategy is proposed to offer styrene (St) copolymer with intrinsic and catalyst-free upcycling capability by incorporating α -methylstyrene (AMS) units into the copolymer poly(AMS -co- St) (PAS). Compared to polystyrene (PS), the PAS is more susceptible to depolymerizing into St and AMS monomers with higher yields at relatively lower temperature. The yield of liquid chemicals of PAS-4 (26.1 mol% AMS) is up to 93 wt% at 380°C, whereas that PS as control is 78 wt%. The reclaimed liquid chemicals of PAS-4 contain 58.4 wt% St and 37.7 wt% AMS, while the chemicals of PS contain 81.8 wt% St and 4.1 wt% AMS. The introduction of AMS units in PAS leads to a reduction in the liquid chemicals other than St and AMS monomers. The blends of PS and PAMS do not demonstrate the synergistic effect regarding facilitating the PS depolymerization. In addition, the properties of the new PASs prepared with the reclaimed monomers are comparable with those of the virgin PASs. This work proves the concept that recycling efficiency could be boosted by incorporating liable structural units into the copolymer chains and demonstrates a closed-loop of PS up-cycling.
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
Crystals
·
2021
·Vol. 11
·期 9
·1049
·
IF 2.589
Jia Xiang,Bo Wang,Le Fu,Chuanpin Chen,Wenjie Liu,Songwen Tan
Lactose is a commonly used excipient with two isomers. Different isomers have different properties, especially in terms of solubility. This work is mainly to explore the influence of different a/β ratio lactose on drug dissolution. This work has developed novel mesoporous pollen-like lactose anhydrous with tailored α/β ratios as ingredient carriers for controlled dissolution rate. The produced lactose carriers are pollen-like with a particle size of ~15 μm and a mean pore width of ~30 nm. β-lactose anhydrous has a unique FTIR-peak at 948 cm−1, whereas α-lactose anhydrous shows a unique FTIR-peak at 855 cm−1. DSC analysis suggests that the pollen-like α/β-lactose crystals are polymorphs with unique peaks of melting points. XRD analysis suggests that (5:5)α/β-lactose polymorph has high crystalline purity. The loading efficiency (30.6–33.4%w/w) of acetamidophenol within the nanoporous lactose particles is dependent on the surface structure and pore volumes—the pore volumes were found to be 0.0209–0.0380 cm3/g. The release rates of acetamidophenol are lower for lactose with high α/β ratios. The lactose solubility and the first-order release constant can be tailored by changing the proportion of β-lactose in the pollen-like lactose carriers.Keywords:pollen-like anhydrous lactose;α/β ratio;solubility;controlled release
研究领域:
药剂学
·
材料科学
✓ 已验证
DOI
高影响因子
CRYSTENGCOMM
·
2021
·Vol. 23
·期 43
·7602-7614
·
IF 3.545
Chao Feng,Gaoyan Xiong,Yaping Li,Qianqian Gao,Yuan Pan,Zhaoyang Fei,Yanpeng Li,Yukun Lu,Chenguang Liu,Yunqi Liu
Determining the effect of crystal facets on reaction performance is essential for designing an efficient propane oxidation catalyst. Herein, α-MnO2 nanowires with exposed (110), (211), (310) and (200) facets were proposed, and their crystal facet-dependent reactivity to propane oxidation was investigated. The resultant α-MnO2 nanowires with predominantly exposed (110) facets showed the maximum propane oxidation activity (T90 = 262.1 °C), oxidation rate, and turnover frequency (at 230 °C), and high stability during the oxidation of propane. In situ diffuse reflectance infrared Fourier transform spectroscopy revealed that the oxidation to form carboxylates is the decisive step; therefore, the production of reactive oxygen species is very important. The results from density of states computations revealed that the lowest electron energy was present in the (110) facet, which helps in the generation of reactive oxygen species and the regulation of the surface valence of Mn. The characterization and calculation results indicated that the (110) facets are conducive to forming oxygen vacancies, which allowed the activation and adsorption of O2 and propane, resulting in significantly enhanced propane oxidation activity. Apart from offering new insights about the structure–activity relationship of α-MnO2 with different facets exposed for short-chain volatile oxidation reactions, this study proposes a technique that can be used for improving other manganese-based catalyst oxidation systems.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2024
·
IF 4.7
Rui Zhu,Yaxin Wang,Minshu Cui
A strategy for the photocatalytic conversion of α-amino acids into corresponding amides was developed. A series of carbon nitride samples were prepared as the catalyst. Various characterizations of the catalyst indicated that effective photocatalytic activity and low recombination efficiency of photo-generated carriers were significant for the high activity of the catalyst. Reaction conditions for the photocatalytic decarboxylation of α-amino acids were optimized, alongside an investigation into the potential mechanism through controlled experiments and DFT computations. Mechanism studies unveiled that photo-generated electrons activated O 2 to reactive oxygen species, while photo-generated holes induced the decarboxylation reactions by activating the carboxylic acid groups, generating carbon radicals that ultimately lead to the formation of corresponding amides under the influence of reactive oxygen species. Moreover, the photocatalytic decarboxylation of different alpha amino acids was also discussed, providing new strategies for the formation of amides and lactams.
研究领域:
有机化学
·
催化化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 75
·61239-61248
·
IF 3.84
Jun Liu,Wei Wu,Qingyong Tian,Shuanglei Yang,Lingling Sun,Xiangheng Xiao,Feng Ren,Changzhong Jiang,Vellaisamy A. L. Roy
Plasmonic photocatalysts coupled with semiconductors are one of the most popular combinations in environmental remediation applications. In this regard, a novel tube-like α-Fe2O3@Ag/AgCl hybrid structure is fabricated by anchoring Ag/AgCl hybrid nanoparticles on the surface of α-Fe2O3 short nanotubes (SNTs) by a step-by-step strategy. Firstly, the monodispersed α-Fe2O3 SNTs have been synthesized via an anion-assisted hydrothermal process followed by the loading of Ag nanoparticles on the surface of α-Fe2O3 SNTs through the classic silver mirror reaction mechanism. From in situ oxidation of Ag nanoparticles, the final product α-Fe2O3@Ag/AgCl heterostructures has been obtained. We study the morphology, composition, and photocatalytic properties of the as obtained tube-like α-Fe2O3@Ag/AgCl nano-heterostructures. The photocatalytic activities of as obtained photocatalysts have been tested by the degradation of organic dye Rhodamine B (RhB) under simulated sunlight (UV + visible light), visible light and UV light irradiation. The main reason for the enhanced photocatalytic performance is attributed to the broad spectral response from the combination of narrow/wide bandgap semiconductors with metallic Ag nanoparticles and efficient charge transfer from plasmon-excited Ag nanoparticles to α-Fe2O3 and AgCl. Finally, this hybrid structure provides a roadmap for the controlled synthesis of plasmonic photocatalysts with excellent properties, and can be used for practical application in environmental issues.
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
DALTON TRANSACTIONS
·
2017
·Vol. 46
·期 7
·2310-2321
·
IF 4.029
Lianwei Shan,Yuteng Liu,Hongtao Chen,Ze Wu,Zhidong Han
We prepared an α-Bi2O3/BiOBr core–shell heterojunction via a facile in situ chemical transformation method. Ultrathin BiOBr nanosheets were observed and these were found to be evenly distributed on the surface of α-Bi2O3/BiOBr by SEM and TEM. The results revealed that the prepared α-Bi2O3/BiOBr photocatalysts were porous, and their specific surface areas were found to be raised on comparing with α-Bi2O3 and BiOBr. In our experiments, the photocatalytic activity of α-Bi2O3 was obviously enhanced when assembling with ultrathin BiOBr compared with α-Bi2O3/BiOBr and the individual phase. It is considered that the surface porous structure increases the specific surface areas, which improved the adsorption characteristics of α-Bi2O3/BiOBr. The suitable band alignment (between α-Bi2O3 and BiOBr) and oxygen vacancy effect can be attributed to the increased photocatalytic activity under visible irradiation.
研究领域:
材料科学
·
物理化学
·
纳米科技
·
催化化学
✓ 已验证
DOI
高影响因子
Nature Communications
·
2025
·Vol. 16
·期 1
·1-8
·
IF 15.7
Hong Cheng-Bin,Hua Wangde,Liu Lieke,Liu Haichao
α-Ketoglutaric acid (KGA) and methanetriacetic acid (MTA) are important multi-functional carboxylic acids with versatile applications. However, their synthetic processes are still not green and efficient. Herein, we report a novel one-pot approach for sustainable synthesis of KGA and MTA from biomass-derived pyruvic and glyoxylic acids under mild conditions. KGA is synthesized via cross-aldol condensation of pyruvic and glyoxylic acids to 2-hydroxy-4-oxopentanedioic acid, followed by its sequential dehydration and hydrogenation on Pd/TiO 2 , affording a high yield of 85.4% on a molar basis of glyoxylic acid at 110 °C and 1.0 MPa H 2 . The synthesis of MTA involves cross-aldol condensation of KGA and glyoxylic acid to 3-(carboxymethyl)-2-hydroxy-4-oxopentanedioic acid and its subsequent hydrodeoxygenation on Pd/TiO 2 and MoO x /TiO 2 in a high yield of 86.2% at 200 °C and 2.0 MPa H 2 . This novel approach provides a rationale for the sustainable production of various multi-functional carboxylic acids that are still not easily available.
研究领域:
生物化学
·
绿色化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS CHEMISTRY
·
2011
·Vol. 21
·期 38
·15009-15014
·
IF 5.101
Jiangbo Hu,Anas Ramadan,Fang Luo,Bin Qi,Xiaojiao Deng,Ji Chen
We introduce an easy and scalable approach to synthesize α-MoO3-decorated graphene sheets from a graphite electrode by molybdate-assisted electrochemical exfoliation. The samples were examined by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transformation infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray diffraction and thermogravimetric analysis. TEM analysis shows that the exfoliated material consists of mainly a few-layers of graphene and the results of XPS, FT-IR and Raman confirmed the presence of α-MoO3 on the graphene sheets. Moreover, XPS spectra indicate that the content of surface oxygen groups on the graphene sheets is lower than that on graphite oxide. After being heat-treated at low-temperature (200 °C), samples exhibited high conductivity (up to 5367 S m−1) and good specific capacitance (up to 86.3 F g−1) when tested as electrode materials in a supercapacitor.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE SCIENCES
·
2024
·
IF 3.4
Meng-Jie Cui,Imran Muhammad,Jian Feng,Tie-Zhen Ren
The crystal and particle size distribution of α-alumina (α-Al 2 O 3 ) nanoparticles is increasingly important for their potential application. However, it is difficult to produce α-Al 2 O 3 nanoparticles due to the high activation energy barrier making it difficult to obtain a pure α-Al₂O₃. In this paper, α-Al 2 O 3 nanoparticles with an average size of 60 nm in width and about 100–300 nm in length were prepared using isopropanol through thermal treatment at 1200 °C, accompanied by a minor fraction of the θ phase. Addressing the challenge of achieving pure phase α-Al 2 O 3 , Density Functional Theory (DFT) calculation was conducted to explore the energy landscape similarity between the θ and α crystal phases. The results provided valuable insights into obstacles associated with obtaining pure α-Al 2 O 3 , enlightening the relationship between surface electronegativity and crystal phases. Furthermore, X-ray Photoelectron Spectroscopy and electrochemical tests were employed to demonstrate that the α phase could enhance the surface electronegativity of Al 2 O 3 . This comprehensive study not only encompasses the synthesis of Al 2 O 3 nanoparticles but also elucidates the distinctions between α and θ phases. These results offer valuable insights into methods optimizing for the synthesis of pure phase α-Al₂O₃.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Shu Yan,Fan Yang,Xianhui Dong,Chao Zhang,Xinda Xu,Zongtao Chi,Woochul Yang,Wanfeng Xie
Real-time monitoring of triethylamine (TEA) is critical to environmental safety and daily life. However, detailed challenges remain for TEA gas sensors, such as low-cost and facile synthetic methods, and low working temperatures. In this study, a combination of hydrothermal and wet chemical approaches is utilized for the rational construction of α -MoO 3 @WO 3 with a sheet-like nanostructure. Additionally, the sensing performances towards triethylamine are investigated. According to the results, it was found that the α -MoO 3 @WO 3 sensor has a higher response value (80.4) and faster response and recovery times (9/26 s) than those of pristine MoO 3 at low optimum temperature (200 °C). Again, the α -MoO 3 @WO 3 based sensor also demonstrated high selectivity to TEA as well as good stability. The enhancement of the MoO 3 @WO 3 sensor's gas-sensitive mechanism may be attributed to the formation of n-n heterojunction between MoO 3 and WO 3 and the synergistic effect of both.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
RARE METAL MATERIALS AND ENGINEERING
·
2016
·
IF 0.236
Guo Haiying,Jiao Tifeng,Zhang Qingrui,Li Adan,Gao Faming
A simple hydrothermal synthesis method has been designed for the controllable synthesis of cubic α -Fe 2 O 3 nanoparticles. Structural and morphological characterizations of the synthesized products were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The size range of the cubic α -Fe 2 O 3 particles is 130–150 nm. Results indicate that the α -Fe 2 O 3 nanoparticles can be used as an efficient photocatalysts for photocatalytic degradation of Rhodamine B in the presence of hydrogen peroxide, which may provide the design and development of high-efficiency visible-light photocatalysts for removing toxic dyes from industrial wastewater with a new way and basis.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）