CHEMICAL ENGINEERING JOURNAL
·
2013
·
IF 3.473
Jiale Huang,Cheng Liu,Daohua Sun,Yingling Hong,Mingming Du,Tareque Odoom-Wubah,Weiping Fang,Qingbiao Li
Au/TS-1 catalysts prepared by an eco-friendly and economical bioreduction method were used for the liquid phase epoxidation of styrene to styrene oxide (SO) using aqueous hydrogen peroxide (H 2 O 2 ) as oxidant. The catalysts were characterized by a variety of techniques including FT-IR, DRUV–Vis, UV–Vis, N 2 physisorption, XRD, XPS, TG–DTG and TEM. The influence of various parameters (Au loading, calcination, solvents, oxidants, reaction temperature, reaction time and catalyst amount) on the catalytic performance was systematically investigated. The results showed that both the conversion of styrene and selectivity to SO were improved and enhanced when catalyzed by biosynthesized gold nanoparticles (GNPs) supported on TS-1. However, decomposing the Cacumen Platycladi ( CP ) biomass properly through calcinations can enhance the catalytic performance though it acted as reductant and protective agents during the catalysts preparation. Besides, the optimum catalytic activity and stability of bioreduction Au/TS-1 catalysts were obtained under operational conditions of Au loading of 1.0 wt.%, CP extract (10 g L −1 ) as reductant, calcined at 723 K for 2 h, reaction time of 10 h, reaction temperature of 333 K, catalyst amount of 500 mg, aqueous H 2 O 2 (30 wt.%) as oxidant and N,N-dimethylformamide as solvent. Under the optimal condition, styrene conversion of 92.7% and SO selectivity of 90.4% was achieved, which were comparable or even superior to those reported in the literatures. The catalyst was reused five times, without significant decrease in both the styrene conversion and SO selectivity.
研究领域:
催化化学
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环境科学
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材料科学
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产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2021
·
IF 8.271
Yuyao Wang,Li Li,Risheng Bai,Shiqin Gao,Zhaochi Feng,Qiang Zhang,Jihong Yu
Tailoring the Ti coordination states in titanosilicate zeolites to simultaneously improve feedstock conversion and maximize the target product selectivity remains a challenge in the pursuit of high-performance catalysts for selective oxidation reactions. Herein, we provide a facile strategy to synthesize hierarchical anatase-free TS-1 ( MFI -type) zeolites with tetrahedrally coordinated (TiO 4 ) and octahedrally coordinated Ti species (TiO 6 ). The TiO 4 species provide high epoxide selectivity, while the TiO 6 species afford improved alkene conversion. This strategy is achieved by synergistically using an L-lysine-assisted approach and a two-step crystallization; the two-step crystallization approach prevents the formation of anatase TiO 2 , while L-lysine stabilizes the TiO 6 species and ensures efficient incorporation of TiO 6 into the anatase-free TS-1 zeolites. Compared with their conventional counterparts, which only contain TiO 4 species, the as-prepared TS-1 zeolites (Si/Ti = 36.9) result in a higher 1-hexene conversion (33%), higher TON value (153), and comparable epoxide selectivity (95%). This synthetic strategy provides avenues to tailor the amount and distribution of Ti species in titanosilicate zeolites to achieve high catalytic performances in various processes.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Haihui Liu,Xiaoxia Zhou,Kangli Xu,Heng Zhang,Huan Wang,Hongqing Zhou,Hangrong Chen
Excessive CO 2 emission has caused serious environmental problems, and converting CO 2 to high value-added fuels is attractive for solving energy and environmental crisis. Herein, a novel mesoporous TS-1(mTS-1) zeolite-confined metal oxides nanoclusters Cu-Bi@mTS-1 was developed for efficient photoelectrochemical reduction reaction of CO 2 (PEC CO 2 RR). The catalyst Cu-Bi@mTS-1 as a photocathode showed high activity, achieving a maximum methanol Faraday efficiency (FE CH3OH ) of 93.4 % at −0.7 V vs. RHE. The C 2 product ethanol could be also detected at higher potentials during PEC CO 2 RR. In-situ FTIR results indicate the occurrence of key reaction intermediates *CO, *CHO, *OCCO and *COCHO during the conversion of CO 2 to CH 3 OH and CH 3 CH 2 OH. It is believed that the hierarchically porous structure of mTS-1 is conducive to the enrichment of CO 2 molecules to increase the reactant concentration, also can promote C-C coupling through photoelectric synergism. This work provides a favorable reference for the rational design of photocathodes by confinement effect of porous structure.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
·
IF 5.518
Guojun Lv,Yan Chen,Xuyang Zou,Jiangzhang Wang,Tao Wang,Xubin Zhang,Fumin Wang
There are few reports concentrated on the interactions between lipophilic surfactants and hydrophobized hollow TS-1 zeolite particles in the stabilization of emulsions. In this study, hydrophobized hollow TS-1 zeolite particles were synthesized and applied as emulsifier to stabilize the W/O Pickering emulsions employing cyclohexanone and water, and the influence of addition of lipophilic Span 80 on the stability of the W/O Pickering emulsions was systematically studied. Surprisingly, a phase inversion was induced by simply changing the Span 80 concentration. At fixed concentration of TS-1 zeolite particles (2 wt%), emulsions are water in oil (W/O) when the concentration of Span 80 is lower than 0.5 mM. Then the emulsions invert to oil in water (O/W) when the Span 80 concentration is between 1 mM and 8 mM. In this process, different emulsifiers dominate the composition of the interfacial layer, and the emulsion type is correspondingly controlled. When Span 80 concentration is lower than 0.5 mM, hydrophobized hollow TS-1 zeolite particles are in domination, and W/O emulsions are obtained. At Span 80 concentration of 1–8 mM, the emulsions are stabilized mainly by Span 80, and the emulsion type is O/W.
研究领域:
化学工程
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材料科学
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界面化学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
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2020
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IF 4.825
Xiaojing Song,Xiaotong Yang,Tianjun Zhang,Hao Zhang,Qiang Zhang,Dianwen Hu,Xinyu Chang,Yingying Li,Ziyi Chen,Mingjun Jia,Peng Zhang,Jihong Yu
Developing an effective strategy to synthesize perfect titanosilicate TS-1 zeolite crystals with desirable morphologies, enriched isolated framework Ti species, and thus enhanced catalytic oxidation properties is a pervasive challenge in zeolite crystal engineering. We here used an amino acid l-carnitine as a crystal growth modifier and ethanol as a cosolvent to regulate the morphologies and the Ti coordination states of TS-1 zeolites. During the hydrothermal crystallization process, the introduced l-carnitine can not only tailor the anisotropic growth rates of zeolite crystals but also induce the formation of uniformly distributed framework Ti species through building a suitable chemical interaction with the Ti precursor species. Condition optimizations could afford the generation of perfect hexagonal plate TS-1 crystals and elongated platelet TS-1 crystals enriched in tetrahedral framework Ti sites (TiO4) or mononuclear octahedrally coordinated Ti species (TiO6). Both samples showed significant improvement in catalytic activity for the H2O2-mediated epoxidation of alkenes. In particular, the elongated platelet TS-1 enriched in “TiO6” species afforded the highest activity in 1-hexene epoxidation, with a turnover frequency (TOF) of up to 131 h–1, which is approximately twice as high as that of the conventional TS-1 zeolite (TOF: 65 h–1) and even higher than those of the literature-reported TiO6-containting TS-1 catalysts derived from the hydrothermal post-treatment of TS-1 zeolites. This work demonstrates that the morphologies and the titanium coordination states of TS-1 zeolites can be effectively tuned by directly introducing suitable crystal growth modifiers, thus providing new opportunities for developing highly efficient titanosilicate zeolite catalysts for important catalytic applications.
研究领域:
材料科学
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催化化学
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晶体工程
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DOI
高影响因子
MOLECULES
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2023
·Vol. 28
·期 7
·3068
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IF 4.6
Yuanyuan Ma,Wanting Liu,Zhifang Li,Yuhang Sun,Mingyuan Shi,Zheng Nan,Ruotong Song,Liying Wang,Jingqi Guan
TS-1 zeolite with desirable pore structure, an abundance of acidic sites, and good thermal stability promising as a support for the selective catalytic reduction of NO with NH3(NH3-SCR). Herein, a series of Mn–Fe/TS-1 catalysts have been synthesized, adopting tetraethylenepentamine (TEPA) as a metal complexing agent using the one-pot hydrothermal method. The introduced TEPA can not only increase the loading of active components but also prompts the formation of a hierarchical structure through decreasing the size of TS-1 nanocrystals to produce intercrystalline mesopores during the hydrothermal crystallization process. The optimized Mn–Fe/TS-1(R-2) catalyst shows remarkable NH3-SCR performance. Moreover, it exhibits excellent resistance to H2O and SO2at low temperatures. The characterization results indicate that Mn–Fe/TS-1(R-2) possesses abundant surface Mn4+and Fe2+and chemisorbed oxygen, strong reducibility, and a high Brønsted acid amount. For comparison, Mn–Fe/TiO2displays a narrower active temperature window due to its poor thermostability.Keywords:Mn-Fe/TS-1;one-pot synthesis;NH3-SCR;metal complexing;resistance to H2O and SO2
研究领域:
催化化学
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环境科学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF POROUS MATERIALS
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2024
·Vol. 31
·期 3
·793-808
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IF 2.5
Yang Zhaosheng,Tang Guoqiang,Li Yichuan,Niu Xiaoyue,Cheng Lingyao,Chai Yongming
TS-1 molecular sieve spherical membranes loaded on small-sized carriers with hierarchical pore structures and high framework-titanium contents could both exhibit high catalytic performances and facilitate the separation from the products after the reaction. In this paper, a simple in situ static crystallization method was used to achieve the construction of hierarchical porous TS-1 molecular sieve membranes on the surfaces of 400-µm spherical ZrO 2 carriers using cetyltrimethylammonium bromide (CTAB) and soluble starch as mesoporous templating agents. Through the catalyst characterization and performance evaluation, soluble starch was finally selected as the mesoporous templating agent, and the film-forming mechanism was investigated by examining the effects of the proportion of precursor liquid and the crystallization conditions. In the chloropropene epoxidation reaction, the effective utilization of H 2 O 2 and the selectivity of epichlorohydrin (ECH) reached 96.72% and 93.85%, respectively.
研究领域:
化学工程
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催化科学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2019
·
IF 3.375
Yunpeng Hu,Kai Wang,Chunli Han,Tao Wang,Guangsheng Luo
A novel liquid–liquid microdispersion method for the synthesis of TS-1 has been developed by continuous preparation of the precursor. In the novel process, the solution of TBOT in n-hexane could be very uniformly dispersed into the oligomeric silicate prehydrolysis mixture to form microdroplets by a microsieve pore reactor. Due to the fast mixing and very high mass transfer performance of the microdispersion process, the Ti species could be uniformly distributed into the mixture and were more likely to condense into the oligomeric silicate precursor species rather than appear with self-condensation. The prepared samples had a minimum molar ratio of Si/Ti at 51 without extra-framework Ti species. Furthermore, the solvent of n-hexane can be recycled by simple phase separation rather than evaporation under the conditions of using isopropanol, which reduced energy consumption. This continuous microdispersion technology could be controllable and a reliable scaling-up for the preparation of TS-1.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
ACS Omega
·
2023
·
IF 4.1
Guoqiang Tang,Yichuan Li,Zhaosheng Yang,Yu Wang,Guangyun Li,Yilou Wang,Yong-Ming Chai,Chenguang Liu
Titanium silica (TS-1) membrane catalysts grown on the surfaces of spherical substrates can both exploit the high catalytic performance and facilitate their separation from products after the reaction. In this work, a simple static crystallization method was used to perform the in situ construction of a TS-1 membrane on the surfaces of micron-sized spherical carriers. The shortcomings of the TS-1 membrane under static crystallization conditions were overcome by in situ dynamic crystallization, and the effect of rotation speed on the formation of the molecular sieve membrane was investigated. The results showed that the molecular sieve membrane was smooth and homogeneous, with a higher synthesis efficiency at a slow rotational speed. The micron TS-1 spherical membrane catalytic chloropropene epoxidation reaction was investigated in a fixed bed, and the conversion of hydrogen peroxide and selectivity of epichlorohydrin reached 99.4 and 96.8%, respectively. After being reused twice, the catalyst still maintained a stable catalytic performance.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Yichuan Li,Xinyan Zhang,Mingxing Luan,Yuntong Zhao,Shibin Feng,Zhaosheng Yang,Bin Liu,Yongming Chai
Molecular sieve membranes are widely used in separation and catalysis due to their good chemical and thermal stability, resistance to contamination, long life, and easy modification. Although immobilized molecular sieve membranes combine catalytic reactivity with recycling separation properties, preparing high-performance TS-1 molecular sieve membrane catalysts is still challenging. In this study, the oriented aggregation of nanocrystals was used in constructing molecular sieve membrane catalysts. By interfering with the crystallization of TS-1, pre-crystal modification with cetyltrimethoxysilane was employed to change the crystal growth behavior. Thus, uniform and dense molecular sieve membranes were prepared through the modulated crystallization of TS-1. This method reduced the requirements of the carrier surface properties for the loading of the membrane layer to enable the construction of membrane layers on carriers of different materials and shapes. Using this method, the effective H 2 O 2 utilization and the epichlorohydrin yield of the micron-sized spherical film catalyst prepared with the inexpensive templating agent TPABr in the chloropropene epoxidation reaction reached 95.89% and 90.22%, respectively.
研究领域:
化学工程
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催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2022
·
IF 5.876
Pengyu Zhao,Zhiguang Li,Yue Zhang,Debao Cui,Qingchun Guo,Zhipeng Dong,Guodong Qi,Jun Xu,Feng Deng
One-step direct hydroxylation of aromatics is an atom-economic way for phenols production. Ti-containing MFI zeolite is considered to be one of the most potential catalysts for hydroxylation of aromatics to phenols under mild condition with aqueous H 2 O 2 as the oxidant. However, the products are often a mixture of mono- or multi-phenols. Designing TS-1 zeolite catalyst with high yield and selectivity to the target phenols remains a challenging task. Here TS-1 zeolites are prepared by direct hydrothermal and post-synthetic methods. Multiple spectroscopic characterizations show that the crystallinity and Ti-Lewis acid sites (Ti-LASs) distribution of TS-1 zeolite can be controlled by the synthetic approach. The structure-activity relationship of TS-1 zeolite is established in the catalytic hydroxylation of anisole, revealing that Ti-LASs concentration determines the conversion of anisole, while both the crystallinity and Ti-LASs distribution significantly influence the selectivity to the desired product para -hydroxyanisole.
研究领域:
催化
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化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2024
·
IF 4.7
Chenyang Zhao,Yujia Liu,Yupeng Tian,Yahui Li,Junjie Feng,Wei Xu,Ning Shi,Zhe Yang,Bing Sun
Direct epoxidation of propylene (C 3 H 6 ) with hydrogen (H 2 ) and oxygen (O 2 ) over Au/TS-1 catalyst was promising way for the synthesis of propylene oxide (PO). However, high selectivity of PO (>95 %) and conversion of C 3 H 6 (>5 %) cannot be achieved at the same time. The industrialization process was severely restricted. In this paper, Au/TS-1 catalysts were synthesized by deposition precipitation method with alkali metal promoter. And alkaline gases and silane coupling post-treatment were performed to promote the catalytic activity. The prepared samples exhibited a much better C 3 H 6 conversion (6.5 %) and PO selectivity (95.1 %) compared with general catalyst using normal synthetic technology. Cs 2 CO 3 was beneficial to increasing Au nanoparticles uptake efficiency. Both NH 3 and triethoxyvinylsilane post-treatment were good for smaller and more uniform loading of Au nanoparticles. The decreasing in surface hydroxyl density effectively alleviated the occurrence of PO ring opening isomerization. The increased hydrophobicity of TS-1 surface was conducive to the rapid desorption of generated PO and significantly increased PO selectivity. Multiple pretreatment was also favorable for extending the lifetime of Au/TS-1 catalyst.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）