EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
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2014
·Vol. 2014
·期 14
·2337-2344
·
IF 2.965
Ling-Yan Meng,Shang-Ru Zhai,Shi Li,Bin Zhai,Qing-Da An,Xiao-Wei Song
Graphical A layer-by-layer deposition strategy was used for the preparation of a tungstophosphoric acid/pentaethylenehexamine/ZrSBA-15 composite. This recyclable material was stable at high temperatures and in polar solvents, and it exhibited excellent catalytic properties (84.7 % conversion, >99 % selectivity) in the selective oxidation of benzyl alcohol (BnOH) to benzaldehyde (BzH). A layer-by-layer deposition strategy was employed for the immobilization of tungstophosphoric acid (HPW) onto a pentaethylenehexamine (PEHA)-grafted ZrSBA-15 framework to a give HPW/PEHA/ZrSBA-15 composite. The resulting composite was characterized by XRD, SEM, TEM, FTIR, thermogravimetric analysis, N 2 sorption, and X-ray photoelectron spectroscopy, and these methods showed that the composite was stable in polar environments. These properties were attributed to the method of preparation, which ensured that a dense and stable array of HPW was encapsulated within the pores of PEHA-modified ZrSBA-15. In the H 2 O 2 -mediated oxidation of benzyl alcohol, the 25 % HPW/PEHA/ZrSBA-15 catalyst exhibited high selectivity (>99 %) for benzaldehyde. Moreover, the oxidation reaction was performed under solvent-free conditions, and the catalyst was recycled several times with negligible loss in selectivity and conversion. This HPW-based catalyst was also efficient at selectively oxidizing other benzylic and alkyl alcohols to the corresponding aldehydes.
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
SCIENCE OF THE TOTAL ENVIRONMENT
·
2020
·
IF 6.551
Srinivasan Vinju Vasudevan,Xianghai Kong,Mengjie Cao,Mei Wang,Hanping Mao,Quan Bu
Tungstophosphoric acid (TPA) encapsulated dendritic fibrous silica KCC-1 was prepared via a microemulsion system with the simple reflux method using cetyltrimethylammonium bromide as a structure-directing agent. The TPA impregnated on KCC-1 (ITPA-KCC-1) was also prepared for comparative. Various physicochemical techniques were used to characterize the synthesized materials and their activity evaluated in the 5-hydroxymethylfurfural (HMF) formation from carbohydrates derivatives of fructose, glucose and cellulose . The effect of various factors such as catalyst to substrate ratio, different solvents and temperature were investigated on the formation of HMF. The resultant encapsulated catalyst was very active in fructose dehydration with the yield of 92% HMF and full conversion of fructose at 120 °C for 30 min under the microwave heating condition without any salt additive in the THF solvent system as well as 95% in MIBK solvent. The HMF yield was achieved by 58% and 16.2% from glucose and cellulose in the DMSO solvent, respectively. The TPA-KCC-1 can be separated easily after reaction from the reaction mixture and reused atleast five times without substantial loss in catalytic activity. This study provides an easy encapsulation method for TPA in dendritic fibrous silica KCC-1 as a heterogeneous catalyst , and it should have great application potential in other biomass valorization processes.
研究领域:
化学工程
·
生物质能转化
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Latif Ullah,Guoying Zhao,Niklas Hedin,Xunlei Ding,Suojiang Zhang,Xiaoqian Yao,Yi Nie,Yanqiang Zhang
Reduction of sulfur-containing compounds from fossil fuel is vital. This work reports on the adsorptive removal of benzothiophene (BT) from liquid fuel using a highly porous metal-organic framework based on a bicomponent zirconium(IV) benzene-tricarboxylate Zr(BTC), and its post-synthetically modified hybrid form with dodeca-tungstophosphoric acid (HPW/Zr(BTC). The HPW loading for the high-performing hybrid adsorbents was 0.5–2.0 wt/wt of W/Zr. Temperature and concentration dependent BT adsorption data were in good agreement with the non-linear Langmuir model combined with a van’t Hoff description of the heat of adsorption. The maximum predicted adsorption capacities were estimated to be 290 and 238 mg.g −1 for HPW(1.5)/Zr(BTC) and Zr(BTC) comparable to the contemporary reported adsorbents. The adsorption kinetics followed a pseudo-second order model, which was related to the low concentration of BT used for these studies. Although the highly porous Zr(BTC) had good adsorptive sites, its adsorption capacity was enhanced by incorporation of HPW, this was attributed to availability of added acid sites for adherence of basic BT. The adsorption findings were further corroborated with DFT calculations, which showed favorable BT adsorption with calculated binding energies of −140.2 and −47.3 kJ.mol −1 for HPW(1.5)/Zr(BTC) and Zr(BTC), respectively. Much of adsorption sites were retained after regeneration of adsorbents.
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
KEY ENGINEERING MATERIALS
·
2012
·
IF 0
Zi Li Liu,Cui Xia Xu,Qian Wen Dai,Chao Xiang,Jian Jie Zhang
Supported H3PW12O40 (HPW) and supported Cesium-Substituted dodecatungsto-phosphate are eco-friendly solid acid catalysts. A series of different loading H3PW12O40/SiO2 and HPW/diatomite were prepared by a typical incipient wetness impregnation of methanol, meanwhile SiO2 and diatomite supported Cs-salt catalysts were prepared via two-step impregnating method. The catalysts were investigated by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The results indicate that the Keggin structure of HPW is intact in the SiO2-supported HPW and SiO2-supported CsHPW. HPW and CsHPW are highly dispersed in the SiO2 at the low loading, while the loading is more than 40% the catalyst grains increase and gather on the surface of the carrier. What's more, diatomite is not a suitable support. HPW and CsHPW have better distribution in the SiO2 than in the diatomite. The activity of catalyst was tested in probe experiment of the alkylation of thiopene (TH) with 1-hexene.
研究领域:
催化化学
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材料科学
✓ 已验证
DOI
MATERIALS CHEMISTRY AND PHYSICS
·
2016
·
IF 2.101
XinWei Shi,Hong Lian,XiaoSheng Yan,Ruiqiong Qi,Ning Yao,Tao Li
Negative thermal expansion Zr 2 WP 2 O 12 (ZWP) powder prepared by hydrothermal method was used as fillers to tailor the thermal expansion coefficient (TEC) of the polyimide (PI)-based composites. A series of PI-based composites containing different loading (0–40 wt% or 0–19.6 vol%) of ZWP powder were fabricated by the in-situ polymerization technique. Their structures and properties were characterized by Scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), Impedance meter, Thermal mechanical analysis (TMA) and Thermogravimetric analysis (TGA). The additions of ZWP steadily reduced the TEC of the PI matrix at all loadings studied. A 40 wt% (19.6 vol%) ZWP loading gives a 32.5% (about 15 × 10 −6 /K) reduction of TEC. The thermal stability of the ZWP/PI composites can be enhanced with the increment of ZWP powder. The independence of the dielectric constant on frequency is improved by introduction of ZWP particles to PIs. The dielectric loss displays good stability, which indicates that the ZWP/PI composites show potential applications in microelectronic and aerospace industries .
研究领域:
材料科学
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复合材料
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热力学
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电子工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Jian-Bo Yang,Jian Wang,Yin-Hua Zhu,Pin-Fang Yan,Zhi-Ming Dong,Hua Mei,Yan Xu
In order to achieve ultra-low sulfur fuel production, it is essential to design highly efficient catalysts for deep desulfurization. In this work, trivacant Keggin-type tungstophosphate PW 9 (Na 9 [A-PW 9 O 34 ]•7H 2 O) was innovatively utilized to synthesize polyoxometalate-based supported silica C 16 -PW 9 /SiO 2 . The intact presence of polyoxometalates (POMs) was evidenced by several techniques of describing the structure and composition of the obtained hybrid samples. Compared with the saturated tungstophosphate ([PW 12 O 40 ] 3− ), the [A-PW 9 O 34 ] 9− showed better coordination, which can coordinate with five ILs (C 16 MIM). More ILs make it easier for the catalyst to attract DBT to the vicinity of PW 9 , and the abundance of metal oxide W = O on PW 9 endows the catalyst’s excellent catalytic activity. Specifically, C 16 -PW 9 /SiO 2 exhibited excellent oxidative desulfurization performance, achieving 100 % dibenzothiophene (DBT) conversion efficiency at 50 °C for 10 min, and the turnover frequency (TOF) number reached 723.4 h −1 , which is higher than the catalysts of the POMs type that have been published. The strategy of combining lacunary polyoxometalates with ionic liquids offers a fresh viewpoint on the creation of POM-based catalysts.
研究领域:
化学
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2021
·Vol. 45
·期 21
·9375-9381
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IF 3.591
Shuping Liu,Xiaowen Su,Dongxue Chu,Chao Ma,Yu Fu,Xiaoshu Qu,Jiahui Lu,Huanan Guan
Polyoxometalates (POMs) with their unique physical and electrochemical nature have been a promising class of electrochromic (EC) materials. Although extensive research has been conducted, much effort has been devoted to the enhancement of the EC properties. Among a variety of factors, the electrolytes exhibit great influences on the EC properties. In this paper, we fabricated a composite film based on nickel-substituted Dawson-type tungstophosphate (P2W17Ni) and TiO2 nanowires by a two-step process involving hydrothermal treatment and a layer-by-layer method (LbL). As a result, the composite film displays transparent to dark blue in both Li+-based non-aqueous and H+-based aqueous electrolytes. Compared to the H+-based electrolyte, the composite film in Li+-based media shows a larger optical modulation of 53.3% and higher coloration efficiency of 85.6 cm2 C−1. The fast switching times of 7.7 s for coloration and 2.2 s for bleaching in Li+-based solution are observed. In addition, the composite film remains almost stable even after 800 cycles in Li+-based solution. The enhancement of the EC properties may be due to the unique nanowire structure, high insolubility and applied potential in Li+-based solution. These results make POMs attractive candidates for EC devices in both non-aqueous and aqueous electrolytes.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2019
·
IF 7.723
Yuli Wei,Zhiwang Yang,Guohu Zhao,Wu Yang
Carbon nanotube sieves (CNTs-S) with a flutelike shape were synthesized by cutting and perforating using a chemical oxidation etching method. Using the obtained CNTs-S as a hard template, SiO 2 -coated CNTs-S dual pore structures (CNTs-S@SiO 2 ) were formed. Finally, tungstophosphoric acid was supported on CNTs, CNTs-S, and CNTs-S@SiO 2 matrices by the incipient wetness method to obtain the corresponding supported catalysts PW 12 /CNTs, PW 12 /CNTs-S, and PW 12 /CNTs-S@SiO 2 . The results showed that obtained 30%PW 12 /CNTs-S and 30%PW 12 /CNTs-S@SiO 2 catalysts in 30 wt% dipping solution had the best catalytic performance for Baeyer–Villiger oxidation of cyclic ketones by H 2 O 2 . The conversion of cyclohexanone was 94% and 91%, respectively, in 5 min under microwave irradiation. Cyclopentanone and adamantanone approached quantitative conversion and the selectivity of corresponding lactones reached 100%. The dual pore structure catalyst showed very excellent cyclic stability.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2016
·
IF 2.848
Fan Wang,Zehui Zhang
In this study, a new method was developed for the oxidation of 5-hydroxymethylfurfural (HMF) into 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) over heterogeneous Ru catalyst. Cs-substituted tungstophosphate (CsPW) was prepared by the exchange of H + in H 3 PW 12 O 40 with Cs + , which was then used to immobilize Ru nanoparticles to give the Ru/CsPW catalyst. The Ru/CsPW catalyst was well characterized by TEM, XRD, XPS and FT-IR technologies. The physical characterizations clearly indicated that the spherica Ru nanoparticles with an average size of 2.4 nm were homogeneously dispersed on the surface of the CsPW support. The as-prepared catalyst was studied for the oxidation of HMF, and some important parameters were investigated. The reaction solvent showed a great effect on both HMF conversion and the products selectivity. Aromatic solvents were found to be the best reaction medium for the oxidation of HMF into HMFCA. Increasing the reaction temperature and the amount of the Ru/CsPW catalyst accelerated the HMF conversion and HMFCA yield. High HMF conversion of 97.2% and HMFCA yield of 72.9% were obtained after 12 h at 130 °C with oxygen flow rate of 20 ml/min. Unfortunately, the Ru/CsPW catalyst was not very stable during the reaction, and a slight loss of its catalytic activity was observed during the recycling experiments.
研究领域:
化学
·
催化材料
·
绿色化学
✓ 已验证
DOI
高影响因子
Journal of Cleaner Production
·
2021
·
IF 9.297
Fengjiao Lai,Feng Yan,Yingqing Wang,Chunyan Li,Jianjun Cai,Zuotai Zhang
Biomass-derived carbohydrates exploited toward the synthesis of alkyl levulinates is very promising, but still limited by the applicable catalyst. In this study, novel metal/Si-pillared montmorillonite supported phosphotungstic acid catalysts (SG-HPW-XSiMt-y, where X = La 3+ , Ce 3+ , Er 3+ , Cu 2+ , Al 3+ , Ti 4+ , Zr 4+ ) were synthesized by sol-gel method. The catalytic performance of SG-HPW-XSiMt-y were comprehensively studied for glucose methanolysis to methyl levulinate (ML), focusing on the effects of metal acidity, HPW contents and reaction conditions. The appropriate Lewis acidity of metal ions effectively facilitated the isomerization of glucose/methyl-glucoside to fructose/methyl-fructoside; the strong Brønsted acidity of incorporated HPW was capable of suppressing the side reactions; and the large specific surface area and hierarchical pores of the mesoporous structure allow the reaction to take place both on surface and inside the porous framework. Among these as-synthesized catalysts, the SG-HPW-ZrSiMt-20 showed the most superior activity and achieved 65.8% yield of ML from glucose at 170 °C for 4 h. Alternative biomass-derived carbohydrates, including fructose, sucrose and cellobiose, also gave excellent ML yields under such catalytic system . The SG-HPW-ZrSiMt-20 had impressively stable reusability with merely loss of catalytic activity after eight cycles, owing to the uniform dispersion and stable bonding of HPW with ZrSiMt support. Generally, this catalyst system realizes an efficient and sustainable conversion of biomass-derived carbohydrates to ML production.
研究领域:
化学工程
·
生物质能转化
✓ 已验证
产品关联
DOI
高影响因子
ANALYST
·
2023
·Vol. 148
·期 12
·2725-2731
·
IF 4.2
Yuhan Ji,Yupu Wei,Jinghui Shen,Jinlong Zhuo,Mingqi Xu,Yunliang Wang,Jingquan Sha
To improve the peroxidase-like activities of metal–organic frameworks (MOFs) as nanozymes, a ternary MIL-100(Fe)@PMo12@3DGO nanocomposite was designed and fabricated by encapsulating Keggin-type H3PMo12O40 (PMo12) with fast and reversible multi-electron redox processes and an electron-rich structure into MIL-100(Fe), then being covered by three-dimensional graphene (3DGO) with higher conductivity, larger surface area, higher porosity, and better chemical stability. As a consequence, the as-prepared MIL-100(Fe)@PMo12@3DGO nanocomposite exhibits excellent peroxidase-like activities, namely, the lowest limit of detection (0.14 μM) in the range of 1–100 μM for glucose to date, to the best of our knowledge, attributed to the individual and synergistic effects of H3PMo12O40, 3DGO and MIL-100(Fe).
研究领域:
材料科学
·
纳米技术
·
分析化学
✓ 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）