CHINESE JOURNAL OF CATALYSIS
·
2019
·
IF 4.914
Xuejuan Cao,Huai Liu,Junnan Wei,Xing Tang,Xianhai Zeng,Yong Sun,Tingzhou Lei,Geng Zhao,Lu Lin
The production of γ-valerolactone (GVL) from lignocellulosic biomass has become a focus of research owing to its potential applications in fuels and chemicals. In this study, ( n )CuO x -CaCO 3 (where n is the molar ratio of Cu to Ca) compounds were prepared for the first time and shown to function as efficient bifunctional catalysts for the conversion of biomass-derived methyl levulinate (ML) into GVL, using methanol as the in-situ hydrogen source. Among the catalysts with varied Cu/Ca molar ratios, (3/2)CuO x -CaCO 3 provided the highest GVL yield of 95.6% from ML. The incorporation of CaCO 3 with CuO resulted in the formation of Cu + species in a CuO x -CaCO 3 catalyst, which greatly facilitated the hydrogenation of ML. Notably, CuO x -CaCO 3 also displayed excellent catalytic performance in the methanolysis products of cellulose, even in the presence of humins. Therefore, a facile two-step strategy for the production of GVL from cellulose could be developed over this robust and inexpensive catalyst, through the integration of cellulose methanolysis catalyzed by sulfuric acid, methanol reforming, and ML hydrogenation in methanol medium.
研究领域:
化学工程
·
可再生能源
✓ 已验证
DOI
高影响因子
JOURNAL OF PHYSICS D-APPLIED PHYSICS
·
2020
·Vol. 53
·期 16
·164002
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IF 3.169
Xinbo Zhu,Xueli Hu,Xiqiang Wu,Yuxiang Cai,Hongbin Zhang,Xin Tu
In this work, ammonia (NH3) synthesis from N2 and H2 was carried out in a packed-bed dielectric barrier discharge (DBD) reactor, while three kinds of commercial packing materials including acidic γ-Al2O3, alkaline γ-Al2O3 and neutral alumina pellets were employed. The effect of packing materials on plasma-assisted NH3 synthesis was investigated and compared with an unpacked DBD reactor. The results show that the presence of packing materials enhanced the plasma-assisted NH3 synthesis by 15.6% to 44.4% compared to the plasma reaction without a packing. The highest NH3 concentration of 1565.5 ppm was obtained over the alkaline γ-Al2O3 packed plasma reactor. The improvement of packing materials on plasma-assisted NH3 synthesis followed the order of alkaline γ-Al2O3 > neutral γ-Al2O3 > acidic γ-Al2O3 > blank tube only. A series of characterizations were performed to illustrate the structure-performance relationships between plasma-induced NH3 synthesis process and packing materials. The results showed that the basicity of the packing materials played an important role in the plasma-assisted NH3 synthesis process. The reaction mechanisms of NH3 synthesis in the packed-bed DBD reactor were also discussed.
研究领域:
化学工程
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材料科学
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等离子体化学
✓ 已验证
DOI
高影响因子
JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS
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2018
·Vol. 107
·期 3
·511-520
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IF 3.373
Moyuan Qu,Wenqian Xiao,Jiarong Tian,Song Wang,Hong Li,Xue Liu,Xiaoling Yang,Bo Li,Xiaoling Liao
Nanofibrous poly( l -lactic acid) (PLLA) microspheres are extensively studied to be used as cell carriers in the field of tissue engineering because the unique structure can promote cell proliferation and migration. But as injectable scaffold materials, PLLA microspheres easily run off to the soft tissue space because of the lack of cohesive force. It will affect the treatment efficiency and even cause additional inflammatory response. In order to overcome this disadvantage, superparamagnetic γ-Fe 2 O 3 nanoparticles assisted with oxidative polymerization of dopamine were used for surface modification of PLLA microspheres in this study. The results showed that this surface modification had no obvious cytotoxicity, and the modified microspheres possessed the ability to carry seed cells to controllably move to the defect sites with the guidance of magnetic field, which may be able to increase the repair efficiency. Moreover, the characteristic nanofibrous structure was not destroyed after modification, which was able to promote biological activity of cells. This work provides a novel way to produce superparamagnetic nanofibrous microspheres designed for cell microcarriers. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 511–520, 2019.
研究领域:
生物医学材料
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组织工程学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LIQUID CRYSTALS
·
2022
·
IF 2.676
Xiangshen Meng,Jian Li,Yueqiang Lin,Xiaodong Liu,Guoqing Li,Jianwei Zhao,Yingning Miao,Wenjian Li,Wenjiang Ye,Decai Li,Zhenghong He
In this paper, the microstructures of the dilute magnetic PDLC films, doped with low concentrations of γ-Fe2O3 nanoparticles, have hardly changed, but their electric-optical responses have distinctly changed. The experimental results show that the threshold voltage and hysteresis decreased with the increasing concentration of γ-Fe2O3 nanoparticles. Furthermore, at the relatively low concentration of γ-Fe2O3 nanoparticles (samples (0) and (1) according to ϕm of 0 and 0.11%), the reciprocity of the rise time increased nonlinearly with the increasing square of the applied voltage. However, at the relatively high concentration of γ-Fe2O3 nanoparticles (samples (2) according to ϕm = 0.15%), the reciprocity of the rise time increased linearly with the square of the applied voltage. Moreover, the reciprocity of the decay time was independent of the applied voltage and decreased with increasing the concentration of γ-Fe2O3 nanoparticles. These characteristics are due to the adsorption of free ions by γ-Fe2O3 nanoparticles. As a result, the interfacial interaction between liquid crystal droplets and the polymer matrix decreased, and the effective electric field inside the liquid crystal droplets increased.
研究领域:
材料科学
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光学
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2021
·Vol. 11
·期 15
·5062-5076
·
IF 6.119
Na Ji,Xinyong Diao,Zhihao Yu,Zhenyu Liu,Sinan Jiang,Xuebin Lu,Chunfeng Song,Qingling Liu,Degang Ma,Caixia Liu
The hydrogenation of levulinate esters to γ-valerolactone (GVL) is an important step in the transformation of biomass into biofuels. It is attractive to develop new efficient systems for the catalytic transfer hydrogenation (CTH) of levulinate esters to value-added GVL. In this work, a series of MoS2-based supported catalysts were prepared via an impregnation method for the CTH of biomass-derived ethyl levulinate (EL) to GVL. By comprehensive characterization and catalytic measurements, we found that the CTH activity of EL to GVL is closely related to the MoS2 morphology and acid distribution on the support. Among the catalysts with different supports, the AC support with abundant Lewis acid sites and large surface area facilitated the high dispersion of low stacked MoS2 slabs, and the MoS2-acid synergistic catalysis contributed to the superior activity and selectivity. The conversion of EL and the selectivity of GVL reached 97.2% and 91.2% under optimized conditions over the MoS2/AC catalyst (230 °C, 1 MPa H2, 1.5 h), respectively. We also conducted reaction kinetic experiments to reveal the relationship between the active site of the MoS2/AC catalyst and its catalytic performance, and the plausible reaction pathway and mechanism over MoS2/AC was proposed. The catalytic performance gradually declined during recycling tests due to the oxidation of MoS2 and can be easily recovered by resulfuration.
研究领域:
化学工程
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生物质能
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2017
·
IF 4.601
Wei-Tu Li,Xian-Yong Wei,Xue-Ke Li,Xiang-Xue Liu,Zhan-Ku Li,Zhi-Min Zong
Catalysts Ni/γ-Al 2 O 3 , Mg 2 Si/γ-Al 2 O 3 , and Ni-Mg 2 Si/γ-Al 2 O 3 were prepared. Their activities for catalytic hydroconversions (CHCs) of some lignite-related model compounds were examined. For the CHCs of oxydibenzene (ODB), benzyloxybenzene, and oxybis(methylene)dibenzene, the suitable loadings of Ni and Mg 2 Si are 33 and 20% in Ni-Mg 2 Si/γ-Al 2 O 3 , respectively, and the optimal reaction conditions are 4 MPa of initial hydrogen pressure, 240 °C, and 2 h, under which ODB was almost completely converted to cyclohexane. The formation of possible intermediates during the CHC of ODB was discussed. Ni-Mg 2 Si/γ-Al 2 O 3 was proposed to have 3 functions, i.e., activating H 2 to biatomic active hydrogen (H⋯H), releasing H − , and heterolytically splitting H⋯H to release H − as well, resulting in the hydrogenation of aromatic rings and the hydrocracking of C O bonds, respectively.
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
Biotechnology for Biofuels and Bioproducts
·
2024
·Vol. 17
·期 1
·1-16
·
IF 3.3
Wei Xiaoyu,Yang Lijie,Chen Zhen,Xia Wenhao,Chen Yongbin,Cao Mingfeng,He Ning
Background The structural diversity of extracellular polymeric substances produced by microorganisms is attracting particular attention. Poly-gamma-glutamic acid (γ-PGA) is a widely studied extracellular polymeric substance from Bacillus species. The function of γ-PGA varies with its molecular weight (Mw). Results Herein, different endogenous promoters in Bacillus licheniformis were selected to regulate the expression levels of pgdS , resulting in the formation of γ-PGA with Mw values ranging from 1.61 × 10 3 to 2.03 × 10 4 kDa. The yields of γ-PGA and exopolysaccharides (EPS) both increased in the pgdS engineered strain with the lowest Mw and viscosity, in which the EPS content was almost tenfold higher than that of the wild-type strain. Subsequently, the compositions of EPS from the pgdS engineered strain also changed. Metabolomics and RT-qPCR further revealed that improving the transportation efficiency of EPS and the regulation of carbon flow of monosaccharide synthesis could affect the EPS yield. Conclusions Here, we present a novel insight that increased pgdS expression led to the degradation of γ-PGA Mw and changes in EPS composition, thereby stimulating EPS and γ-PGA production. The results indicated a close relationship between γ-PGA and EPS in B. licheniformis and provided an effective strategy for the controlled synthesis of extracellular polymeric substances.
研究领域:
微生物学
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生物化学
·
合成生物学
✓ 已验证
DOI
PubMed
高影响因子
GREEN CHEMISTRY
·
2017
·Vol. 19
·期 9
·2201-2211
·
IF 9.125
Wenxiu Cao,Wenhao Luo,Hongguang Ge,Yang Su,Aiqin Wang,Tao Zhang
The hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) is a crucial reaction included in many biorefinery schemes for the production of renewable chemicals and fuels. The development of highly stable supported Ru-based catalysts in the polar protic liquid phase under hydrothermal conditions is still a major challenge. Here, we prepared a 0.85 wt% Ru/ZrO2@C catalyst using a new stabilization strategy based on the UiO-66 (Zr-MOF) material. The catalytic performance of this Ru/ZrO2@C in LA-to-GVL was tested and compared with commercial 5 wt% Ru/C at 10 bar H2, 413 K in water and also in high protic aqueous solution (pH = 1). The full conversion of LA and quantitative yield of GVL were achieved with both catalysts. However, the 5 wt% Ru/C showed poor resistance to deactivation already after the first run. ICP, XPS, HRTEM, AC-STEM, TPR and physisorption data showed that quick deactivation of Ru/C was mainly caused by the leaching of ruthenium in addition to the loss of surface area via carbonaceous deposition in micro-pores. In contrast, the self-prepared Ru/ZrO2@C catalyst showed no apparent drop in catalytic performance either in water or in high protic aqueous solution upon multiple recycling, and no leaching of ruthenium was found even under harsh conditions (pH = 1). Remarkably, in the Ru/ZrO2@C catalyst, Ru (probable single-atom) was highly dispersed on nanotetragonal ZrO2 (3.3 nm), embedded in the amorphous carbon, and no apparent Ru nanoclusters were observed even after reactions. TPR results indicated that this excellent stability might be attributed to strong metal–support interaction between Ru and nanotetragonal ZrO2.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2015
·
IF 4.494
Zhiping Xu,Wenzhi Li,Zhijie Du,Hao Wu,Hasan Jameel,Hou-min Chang,Longlong Ma
A novel solid acid catalyst was prepared by the copolymerization of p-toluenesulfonic acid and paraformaldehyde and then characterized by FT-IR, TG/DTG, HRTEM and N 2 -BET. Furfural was successfully produced by the dehydration of xylose and xylan using the novel catalyst in γ-valerolactone. This investigation focused on effects of various reaction conditions including solvent, acid catalyst, reaction temperature, residence time, water concentration, xylose loading and catalyst dosage on the dehydration of xylose to furfural. It was found that the solid catalyst displayed extremely high activity for furfural production. 80.4% furfural yield with 98.8% xylose conversion was achieved at 170 °C for 10 min. The catalyst could be recycled at least five times without significant loss of activity. Furthermore, 83.5% furfural yield and 19.5% HMF yield were obtained from raw corn stalk under more severe conditions (190 °C for 100 min).
研究领域:
化学工程
·
生物质能
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CATALYSIS TODAY
·
2017
·
IF 4.636
Zhijie Wu,Min Zhang,Yirong Yao,Jingtuo Wang,Danhong Wang,Minghui Zhang,Yongfeng Li
1,3-propanediol (1,3-PDO) and γ-valerolactone (GVL) were simultaneously obtained via the hydrogenolysis of glycerol in levulinic acid (LA) using Ru/C catalysts. Ru/C catalyst exhibited a high LA conversion (∼99%) and a high GVL selectivity (∼99%) for the hydrogenation of LA; while a low conversion (∼11%) and little selectivity of 1,3-PDO for the hydrogenolysis of glycerol. LA promoted the hydrogenolysis of glycerol over Ru/C catalyst, in which LA catalyzed dehydration of glycerol into acetol (precursor of 1,2-propanediol (1,2-PDO)), and glycerol acetalization with the hydrogenated GVL into cyclic acetals, resulting in the formation of 1,3-PDO. A reaction scheme involves the formation of cyclic acetal ethers between GVL and glycerol was proposed to explain the product distributions in the one-pot synthesis of 1,3-PDO and GVL. 64.5% conversion of glycerol and 35.8% selectivity of 1,3-PDO together with 99.1% conversion of LA and 85.8% selectivity of GVL were obtained during one-pot converting glycerol and LA with 3.0 MPa H 2 at 200 °C for 6 h. We reported an effective strategy for the preparation of 1,3-PDO by selective hydrogenolysis of dioxan originated from glycerol with aldehydes or ketones.
研究领域:
生物化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2022
·
IF 6.364
Shenglin Kang,Xuetong Zhao,Jing Guo,Jie Liang,Jianjie Sun,Yang Yang,Lijun Yang,Ruijin Liao,Clive A. Randall
Thermal-assisted cold sintering process (TA-CSP) has been applied to fabricate high dense α-Al 2 O 3 ceramics with submicron grain sizes. The α-Al 2 O 3 (80 wt%) and γ-Al 2 O 3 (20 wt%) powders are firstly mixed and then cold sintered at 300 °C to produce a green bulk with a relatively high density of ∼ 86.9 %, and then later a second heat treatment (800–1350 °C) is applied to finally fabricate (∼ 98 % dense) α-Al 2 O 3 ceramics with grain sizes of 720 nm. A microstructural analysis with XRD and TEM suggests that the TA-CSP samples not only complete the final densification but also drive a phase transition of γ-Al 2 O 3 to α-Al 2 O 3 . To put into perspective the Hardness and Young's modulus of TA-CSP samples reach ∼ 14 GPa and ∼ 335 GPa, respectively, which is comparable to conventional sintered samples processed at higher temperatures of 1500–1700 °C. Therefore, it is feasible to utilize TA-CSP to prepare α-Al 2 O 3 ceramics with small grain sizes at low sintering temperatures .
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2019
·Vol. 21
·期 17
·2799-2808
·
IF 3.382
Yunpeng Liu,Lixiong Qian,Xiaoyi Zhao,Jiayi Wang,Lei Yao,Xueqing Xing,Guang Mo,Quan Cai,Zhongjun Chen,Zhonghua Wu
Composites with hierarchical structures have wide potential applications in the catalyst industry. In this paper, a self-assembled 3D flower-like architecture of the Bi/γ-Fe2O3 composite has been successfully synthesized without employing any surfactants and templates via a facile and economical hydrothermal method. Its formation process has been studied. X-ray diffraction (XRD), X-ray absorption fine structure (XAFS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and Raman spectroscopy techniques were used to monitor the formation process. The results demonstrate that the self-assembled 3D flower-like Bi/γ-Fe2O3 composite consists of a Bi metal nucleus and a γ-Fe2O3 shell. The Bi metal nucleus is identified to be an aggregate of Bi nanoparticles, while the γ-Fe2O3 shell results from the intercrossing of γ-Fe2O3 nanoslices. The time-dependent intermediate products in the self-assembly process were structurally characterized. The influence of concentration and the formation process have been carefully discussed. A possible formation mechanism has been proposed. By virtue of the structural understanding of the novel 3D flower-like Bi/γ-Fe2O3 composite, this work is expected to highlight its potential applications.
研究领域:
材料科学
·
纳米技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）