Journal of Physical Chemistry C
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2018
·
IF 4.484
Zhenzhen Wang,Haoyang Zhang,Lili Chen,Songsong Miao,Shujie Wu,Xiufeng Hao,Wenxiang Zhang,Mingjun Jia
In this work, a series of amine-modified ZrSBA-15-supported PtPd bimetallic catalysts with different Pt/Pd ratios were prepared and characterized by a variety of means. Introducing amino groups on the surface of ZrSBA-15 is beneficial for achieving high dispersion of PtPd nanoparticles (NPs) and can effectively prevent the overgrowth of PtPd NPs during the preparation process. The resulting hybrid catalysts exhibit very high catalytic activity and stability for H2 generation from aqueous ammonia borane (AB) and can also efficiently catalyze the reduction of p-nitrophenol to p-aminophenol using AB as the hydrogen source. Among them, the catalyst with the Pt/Pd ratio of 85/15 shows the highest activity for AB dehydrogenation under ambient condition, whereas the catalyst with the Pt/Pd ratio of 50/50 exhibits the highest efficiency for the reduction of p-nitrophenol with AB. These results suggest that highly efficient interface active sites could be constructed by optimizing the composition of bimetallic PtPd NPs and changing the chemical surrounding of mesoporous ZrSBA-15, which demonstrate effective synergistic catalysis for AB dehydrogenation and p-nitrophenol reduction.
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MICROPOROUS AND MESOPOROUS MATERIALS
·
2018
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IF 3.649
Meng Zhang,Bingxian Chu,Guoying Li,Jianze Xiao,Haowen Zhang,Yujie Peng,Bin Li,Peng Xie,Minguang Fan,Lihui Dong
A series of triethanolamine-modified mesoporous SBA-15 catalysts were synthesized by a facile one-pot process, and used as the catalyst for the synthesis of cyclic carbonates through the cycloaddition of CO 2 with epoxides. The properties of catalysts were characterized by nitrogen adsorption–desorption, elemental analysis (EA), Fourier transform infrared (FT-IR) spectra, Magic angle spinning nuclear magnetic resonance (MAS NMR), X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscopy (TEM), and the results suggested that triethanolamine (TEA) had been successfully immobilized on SBA-15. It was highly active in the cycloaddition reaction, in which the maximum yield of PC could achieve 93.47% under the conditions as follow: catalyst amount of 0.20 g, reaction temperature of 110 °C, reaction pressure of 2.0 MPa and reaction time of 4 h. Notably, the catalyst can be easily recovered by filtration, and it can be retained most of its catalytic stability and activity after five recycling times. On the basis of the experimental results, the interactions between the catalysts and the substrates were studied by DFT calculations, and the possible mechanism for the reaction was proposed.
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MICROPOROUS AND MESOPOROUS MATERIALS
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2013
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IF 3.365
Sen Lin,Lei Shi,Hongpeng Zhang,Na Zhang,Xianfeng Yi,Anmin Zheng,Xuebing Li
Al-SBA-15 containing plug structures inside straight channels have been hydrothermally synthesized through a one-step synthesis strategy in an environmentally friendly acid-free medium. The effects of steaming, alkali, and acid post-treatments on the structural properties were investigated by powder X-ray diffraction (XRD), nitrogen adsorption–desorption at 77 K, transmission electron microscopy (TEM), scanning electron microscopy (SEM), FT-IR spectrum, 27 Al MAS NMR, and inductively coupled plasma (ICP) analyses. The presence of the plugs can significantly enhance structural stability against steaming or alkali post-treatments. Acid post-treatment can be a very simple and convenient technique for adjusting the textural properties of plug-containing Al-SBA-15, and especially for optimizing the accessibility to active sites. Acid post-treatment at the low temperatures of 313 and 323 K results in the formation of a larger specific surface area (905 m 2 /g) and pore volume (0.94 cm 3 /g) through an “open door” effect in the plugs, without eliminating any of the plugs from the channels. In particular, nearly half of the secondary micropores on the pore walls were preserved. In contrast, raising the acid post-treatment temperature further to 333 and 343 K caused a “closed doors” effect through the blockage of pores in the plugs by the extracted fragments. After loading with nickel, the catalyst exhibited a higher yield of C 10+ olefins in ethylene oligomerization , and more importantly, after steaming and acid post-treatments at higher temperatures, the samples showed shape selectivity for the C 16 olefin.
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JOURNAL OF MOLECULAR LIQUIDS
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2016
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IF 2.74
Jiang Xiao,Yongzhong Jia,Chenglong Shi,Xingquan Wang,Ying Yao,Yan Jing
A novel liquid–liquid extraction system was investigated for the selective separation of lithium isotopes using ionic liquids (ILs = [C 6,8,10,12 mim] + [PF 6 ] － ) as extraction solvent and benzo-15-crown-5 (B15C5) as extractant. The effects of the concentration of lithium salt , counter anion of lithium salt, initial pH of aqueous phase, and extraction temperature on the lithium isotopes separation were studied. The maximum single-stage separation factor α of 6 Li/ 7 Li obtained in the present study was 1.038 ± 0.002, indicating the lighter isotope 6 Li was enriched in organic phase while the heavier isotope 7 Li was concentrated in the aqueous phase. The formation of 2:1 complex Li(B15C5) 2 + in the IL phase was determined on the basis of slope analysis method. The large value of the free energy change (− G 0 = 77.87 J mol −1 ) indicated the high separation capability of the lithium isotopes by B15C5/30%CH 3 Cl-70% C 6 mimPF 6 mixture extraction system. Lithium in Li(B15C5) 2 + complex was stripped by 0.5 mol·L −1 HCl solution. The extraction system offers high efficiency, simplicity application prospect to separation lithium isotope separation from LiCl solution.
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FOOD CHEMISTRY
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2017
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IF 4.529
Hongwu Wang,Yanqing Liu,Su Yao,Peijie Zhu
In this work, a highly selective molecular imprinted polymer (SBA-15@MIP) was prepared using dicyandiamide (DCD) as the template molecule and mesoporous silica SBA-15 as the carrier. The resulting polymers were characterized by scanning electron microscopy and FT-IR spectra. A highly ordered mesoporous nanostructure was observed for the fabricated polymer. The performance tests showed that the adsorption capacity of SBA-15@MIP for DCD was higher than those of non-imprinted mesoporous silica polymer (SBA-15@NIP) and SBA-15. SBA-15@MIP was successfully used as the solid-phase extraction (SPE) sorbent coupled with HPLC for trace DCD determination in bovine milk and milk powder. Under selected conditions, a favorable linearity between 1 μg/mL and 100 μg/mL was obtained and the detection limit was estimated to be 0.08 μg/mL (bovine milk) and 0.10 μg/mL (milk powder). These results indicated that SBA-15@MIP could be used as an efficient SPE adsorbent for enrichment of DCD in bovine milk and milk powder.
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FOOD CHEMISTRY
·
2024
·
IF 8.5
Zifan Hu,Weiyang Sun,Jiaqi Guo,Xuan Wang,Li Yong,Lin Ren,Dejian Feng,Xiaoli Zou
Using high-performance liquid chromatography-mass spectrometry, fifteen bisphenols and halogenated phenols were simultaneously analyzed in tea for the first time in China. Response surface methodology was used to optimize sample preparation conditions based on QuEChERS. Finally, the limits of detection and the limits of quantification were 0.0200–0.173 μg/kg and 0.0892–0.770 μg/kg, respectively. The recoveries were 70 %–120 % for most compounds (except for some compounds at low spiked concentrations) with RSDs <20 %. Then 135 dried tea samples were analyzed. Bisphenol S, A and F were the predominant bisphenol contaminants with detection rates above 80 %, and the median level of bisphenol F (4.90 μg/kg) was even higher than that of bisphenol A (2.74 μg/kg). Bisphenol A ( p < 0.001) and bisphenol F ( p = 0.007) were significantly higher in black tea than in green tea. Hazard index was estimated and bisphenols in tea may pose potential risks to human health.
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Green Chemistry Letters and Reviews
·
2024
·
IF 5.8
Hong Zhang,Wenbin Liu,Lei Wang,Xin Zhang,Bo Wang,Xu Zeng,Bin Zhang
The immobilization of enzymes is an important strategy to improve their stability and reusability. However, it often comes with a trade off of reduced biological activity and catalytic efficiency. In this study, a composite hydrogel based on corn stalk carboxymethyl cellulose, acrylic acid, and mesoporous silica SBA-15 was developed as a support for the immobilization of lipase from Pseudomonas S.P. (PSL). The surface morphology and functional properties of the composite hydrogels were investigated by scanning electron microscopy, Fourier transform infrared, X-ray diffraction and simultaneous thermal analyzer, respectively. The composite hydrogel materials had a large number of mesopores and macropores were present in the wall of the hydrogel sheet. The hydrogel had a network structure that reduced the diffusion resistance of the substrate and improved the accessibility of the enzyme. The immobilized PSL exhibited high enantioselectivity (E value: 88.2) and enzyme activity (316.8 µmol/g/min) in the preparation of (S)-ibuprofen by enzymatic hydrolytic resolution of racemic ibuprofen ethyl ester. This prepared novel composite hydrogel is a promising supporting matrix for the immobilization of enzymes.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2025
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IF 9
Jicheng Wang,Yanhong Quan,Linjie Li,Shunan Yin,Xinxin Ding,Jun Ren
A series of Cu/SBA-15 catalysts with different Cu loadings are prepared by the ammonia evaporation method for the liquid-phase hydrogenation of furfural (FF) to furfuryl alcohol (FA). The results show that the supported Cu loading influences the structure and catalytic activity during FF hydrogenation. The 20Cu/SBA-15 catalyst shows the optimum performance with 99.3 % FF conversion, 99.0 % selectivity to FA, nearly pure FA product, and a turnover frequency reaching up to 81.7h −1 . The effect of Cu loading can be related to Cu dispersion and the interaction between the metal and support, which further promotes the surface Cu + /Cu 0 ratio. Additionally, the correlation of FF conversion with Cu + /Cu 0 ratio confirms that the excellent performance of 20Cu/SBA-15 is mainly derived from the synergy of Cu + and Cu 0 species, although the range of performance is not large. Finally, the optimal reaction conditions are screened using a reaction temperature of 150 °C, a reaction pressure of 4 MPa, a catalyst dosage of 0.1 g, and a reaction time of 60 min. The present study confirms that the Cu loading has a significant effect on the structure of Cu/SBA-15 and nearly pure objective FF product can be feasibly obtained with an appropriate Cu support in the synthesis of FA from FF hydrogenation.
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ACS Sustainable Chemistry & Engineering
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2024
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IF 7.1
Li Cui,Ren Gao,Qiaowei Zhang,Kun Jiang,Hongyan He,Wei-Lu Ding,Fangqin Cheng
Crown ethers (CEs) are promising materials for lithium isotope (6Li and 7Li) separation for their unique cavity structure and size effect, but the low partitioning of Li+ makes the practical implementation not applicable. The loss of CE molecules is also a critical problem. In this work, benzo-15-crown-5 functionalized imidazolium ionic liquids with different alkyl chain lengths ([Cn(B15C5)mim][NTf2], n = 6, 8, 10) are synthesized. The association constants of [Cn(B15C5)mim][NTf2] and Li+, Li+ partition, and the separation factor of 6Li and 7Li using [Cn(B15C5)mim][NTf2] were investigated. Compared with the B15C5 monomer, the covalent bonding of B15C5 onto the cation of imidazolium ILs contributes to the dramatic increase of binding ability toward Li+. The association constants of [Cn(B15C5)mim][NTf2] with Li+ increase with the elevation of the alkyl chain length due to the flexibility changes. However, [C8(B15C5)mim][NTf2] delivers the most outstanding partition coefficient of Li+ up to 7.59 with a separation factor of 1.033 (273 K), exceeding those reported for CE-based materials. The increased hydrophobicity of [Cn(B15C5)mim][NTf2] enables sustainable and robust use in the separation process. Both molecular dynamics simulations and interfacial tension experiments confirm that [C8(B15C5)mim][NTf2] exhibits the best affinity to the interfaces of dichloroethane/water. The coordination environment of Li+ can be tuned by regulating the length of the alkyl chains, resulting in different isotopic effects. This study offers a promising system for the effective and sustainable separation of 6Li and 7Li.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2012
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IF 3.07
Yan-Jing Gu,Bing Yan
A series of new visible and near-infrared (NIR) luminescent lanthanide-hydroxybenz[de]anthracen derivatives (Ln(HBAN) 3 (H 2 O) 2 (NO 3 ) 3 , Ln(HBAN) 3 phen(NO 3 ) 3 ) were synthesized (HBAN-6-hydroxybenz[de]anthracen-7-one, Ln = Eu, Yb, Nd). Further, chemically bonded lanthanide hybrids of functionalized mesoporous silica (SBA-15) are prepared using HBAN-functionalized alkoxysilane (HBAN-Si) as linker, which is named as Ln(HBAN-SBA-15) 3 (NO 3 ) 3 , Ln(HBAN-SBA-15) 3 phen(NO 3 ) 3 (Ln = Eu, Yb, Nd), respectively. The physical characterization and especially the photoluminescence properties for these hybrids are performed. SAXRD and BET of them revealed that all of these hybrid materials have uniformity in the mesostructure. Worth noting here is that the excitation spectra of these hybrid materials are extended to visible light region (439–535 nm). Upon ligand-mediated excitation with the ultraviolet and visible light, the visible luminescence for europium hybrids and NIR luminescence for Yb 3+ and Nd 3+ hybrids are obtained.
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Journal of Environmental Chemical Engineering
·
2025
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IF 7.2
Yang Xiao,Chao Qu,Jingjing Zhang,Xi Chen,Wenjin Wang,Xuelong Zheng,Qing Ye
The dissociation of water is essential to water gas shift (WGS) reaction, and the presence of oxygen vacancies can facilitate this key step. Herein, a series of perovskite supported Pd single atoms catalysts were prepared via deposition precipitation method. The incorporation of Pd single atoms can effectively promote the formation of oxygen vacancy on the surface of the catalyst, improving the low temperature reducibility, the ratio of Mn 4 + /Mn 3+ and O ads /O lat compared with support. Among all samples, 0.82 Pd/La 0.5 Ca 0.5 MnO 3 /SBA-15 with the most oxygen vacancies presented 83.6 % CO conversion at 400 °C, specific reaction rate (0.54 mol CO g Pd −1 h −1 ), and TOF (3.77✕10 −2 s −1 ). DFT calculation proved that Pd doping can effectively decreased energy barrier of H 2 O dissociation, and promoted the formation of oxygen vacancies. This work provides experimental and theoretical insights into the rational design of highly active perovskite supported Pd single atom catalysts for WGS reaction.
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Natural Products and Bioprospecting
·
2024
·Vol. 14
·期 1
·1-16
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IF 4.8
Yang Ya-Ya,Jing Shun-Li,Shao Jia-Li,Chen Ji-Xuan,Zhang Wei-Feng,Wan Si-Yuan,Shen Yu-Ping,Yang Huan,Yu Wei
Functionalized mesoporous materials have become a promising carrier for enzyme immobilization. In this study, Santa Barbara Amorphous 15 (SBA-15) was modified by N-aminoethyl- γ -aminopropyl trimethoxy (R). R-SBA-15 was employed to purify and immobilize recombinant β -glucosidase from Terrabacter ginsenosidimutans (BgpA) in one step for the first time. Optimum pH of the constructed R-SBA-15@BgpA were 7.0, and it has 20 ℃ higher optimal temperature than free enzyme. Relative activity of R-SBA-15@BgpA still retained > 70% at 42 ℃ after 8-h incubation. The investigation on organic reagent resistance revealed that the immobilized enzyme can maintain strong stability in 15% DMSO. In leaching test and evaluation of storage stability, only trace amount of protein was detected in buffer of the immobilized enzyme after storage at 4 ℃ for 33 days, and the immobilized BgpA still maintained > 50% relative activity. It also demonstrated good reusability, with 76.1% relative activity remaining after fourteen successive enzymatic hydrolyses of epimedin A to sagittatoside A. The newly proposed strategy is an effective approach for the purification and immobilization of BgpA concurrently. In addition, R-SBA-15@BgpA was demonstrated to have high efficiency and stability in this application, suggesting its great feasibility and potential to produce bioactive compounds such as secondary glycosides or aglycones from natural products. Graphical Abstract
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危险品化学品经营许可证（带存储）