INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Rui Feng,Zhou Fang,Wei Wang,Tianbo Li,Xiaoyan Hu,Xinlong Yan,Zhongdong Zhang
Direct hydroxylation of benzene to phenol is an environmentally friendly strategy to produce phenol compared with the conventional process. In this work, vanadium-modified titanium silicate-1 (TS-1) with enhanced Lewis acid and charge density were prepared as catalysts for efficient hydroxylation of benzene to phenol in the presence of hydrogen peroxide as an oxidant under mild conditions. The hierarchical TS-1 zeolites with a high framework Ti content were synthesized in the presence of NH4HCO3, and then vanadium doping was used to change the acidity and charge density. It was found that NH4HCO3 favored the titanium substitution of framework sites and nanocrystal stacking of TS-1. Vanadium doping increased the amount of Lewis acid sites and the charge density associated with the framework Ti. The enhancement in acid and electron characteristics boosted the intrinsic catalytic reactivity of Ti-OOH species, which further improved the performances toward benzene hydroxylation. The presented strategy and mechanistic results clarified the relationship between the structure and acidity in TS-1 zeolite. It was also verified that hydroxyl radicals (•OH) rather than superoxide radicals (•O2–) were the reactive agents responsible for the consecutive selective oxidation of benzene.
研究领域:
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ECS Journal of Solid State Science and Technology
·
2023
·Vol. 12
·期 12
·123003
·
IF 2.2
Lirui Shi,Qingyu Wang,Xin Zhou,Zhaoliang Xing,Chuncheng Hao
Nano-composite dielectric materials are considered as the most promising insulating materials for HVDC cables. The effects of different concentration of nano-filler and structure of nanoparticle on the electrical properties of crosslinked polyethylene (XLPE) composites were studied by using three different chemical treated titanium-silicon molecular sieves TS-1 as nano-filler. The experimental results show that the dielectric properties of the composites increased by 17.76%, 19.16% and 16.36%, respectively, after TS-1 and alkali treatment for 12 h and 24 h. After the addition of the first two fillers, the resistivity was nearly doubled to 46.71% and 47.41%, respectively, and the breakdown field strength was increased by 3.40% and 9.28%, respectively. After 24 h alkali treatment, the volume resistivity and breakdown field strength of TS-1 were lower than that of pure XLPE.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 9
·期 10
·6205-6213
·
IF 12.732
Jiacheng Xing,Danhua Yuan,Hanbang Liu,Yansi Tong,Yunpeng Xu,Zhongmin Liu
The synthesis of TS-1 zeolites is regarded as a milestone in zeolite history, and it has led to the revolution of the green oxidation system of using H2O2 as an oxidant, leaving only water as the byproduct. However, because of the highly hydrolyzable titanium source, the preparation of TS-1 requires complex synthesis conditions. Moreover, the difference in the hydrolysis rate between the silicon source and titanium source tends to increase the difficulty of titanium insertion into the framework, and it is easy to generate extra-framework Ti species during the synthesis. Here, a high-quality TS-1 zeolite with a large external surface area and free of extra-framework Ti species has been successfully synthesized by using a kind of novel polymer containing titanium and silicon. Due to the high hydrolysis resistance of the polymer reagent, a good matching of the hydrolysis rate between the silicon source and the titanium source is realized during crystallization, which facilitates the incorporation of titanium into the framework. Furthermore, the TS-1 zeolite exhibited excellent catalytic performance in n-hexane oxidation with hydrogen peroxide as the oxidant. This method of synthesizing zeolites from polymers is expected to be widely applied for the synthesis of other titanium-containing zeotype materials.
研究领域:
化学
·
材料科学
·
催化
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2025
·
IF 3.5
Yuan Li,Shengkai Sun,Hanfang Liu,Wenna Wang,Dehong Chen,Yu Yang,Feng Liu,Bin Yu,Jia Liu,Binjie Li,Lei Wang,Bin Li
Epoxidation of olefin catalyzed by titanium silicalite-1 (TS-1) can obtain important intermediate epoxides of industrial production in a green and pollution-free manner. However, due the problem of macromolecules transport path restraint, which cause the catalyst to fail in lifetime and activity. Strategically, to increase the transport channel of macromolecules and shorten the transport path, it is necessary to introduce mesoporous structures into zeolite. Here, we report a solid-state synthesis of hierarchical TS-1 zeolite by optimizing carbon black sequence. The texture property of hierarchical TS-1 can be optimized by carbon black. Most importantly, the addition sequence of carbon black can impact the porosity of hierarchical TS-1. The hierarchical zeolite is synthesized by incorporating 0.2 g carbon black into the seeds. When carbon black is firstly combined with seeds, the enhanced interaction facilitates the subsequent growth process, leading to large surface area from mesopores (121 m 2 /g) and abundant pores size (8–40 nm) and enhanced exposure of Ti active sites. The optimized hierarchical TS-1 possesses excellent catalytic performance with high conversion rate (24.4 %) and similar selectivity (93.8 %), which are 1.6 times higher than that of traditional TS-1 zeolites.
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
CATALYSIS LETTERS
·
2024
·
IF 2.3
Yin Pengyu,Nie Jiayuan,Wen Xiangyu,Li Zhihui,Zhang Dongsheng,Zhao Xinqiang,Wang Yanji
ε-Caprolactam (CPL) is an important organic chemical raw material used as a monomer in the production of nylon 6. The traditional production process employs fuming sulfuric acid as a catalyst, leading to serious equipment corrosion and environmental pollution. While vapor-phase Beckman rearrangement reaction offers a solution to these issues. Unfortunately, the catalyst used is susceptible to carbon deposition and deactivation during the vapor-phase Beckman rearrangement process. Herein, a kind of mixed acid-modified hollow TS-1 zeolite was prepared in this study. It is a hollow structure of TS-1 zeolite formed by secondary crystallization, which is conducive to the shortening of the reaction path and the improvement of the anti-carbon accumulation performance. Further investigation revealed that modification of the hollow TS-1 zeolite with mixed acids facilitates the removal of non-skeletal titanium, and reduces the amount of Lewis acid in the catalyst, thereby improving its catalytic performance. Under optimal conditions, the cyclohexanone oxime (CHO) conversion rate reached 100%, with a caprolactam selectivity exceeding 98%. Notably, the catalytic activity of the catalyst remained stable after 500 h of continuous operation. Graphical Abstract
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
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2025
·
IF 3.9
Guojun Lv,Linfang Jiang,Yan Chen,Xuyang Zou,Xubin Zhang,Fumin Wang
The addition of an additional mesoporous/macroporous templating agent inevitably has an adverse effect on the economy and greenness of the seed-assisted synthesis process for hierarchical zeolites; hence, the development of an efficient seed-assisted method for the synthesis of hierarchical zeolite without the addition of an additional additive is appealing. Herein, we reported the preparation of hierarchical TS-1 zeolite with a large amount of mesopores using a liquid–solid mixture seed-assisted method and its application as a heterogeneous catalyst in the oxidative desulfurization reactions. The characterization results disclosed that the liquid–solid mixture seed was more conducive to the formation of hierarchical TS-1 zeolite than liquid seed alone and solid seed alone. The formation process of hierarchical TS-1 zeolite with different crystallization times was investigated in detail, and accordingly, a possible two-stage crystallization mechanism was proposed. In addition, the synthesized hierarchical TS-1 zeolite showed remarkably enhanced catalytic activity in the oxidative desulfurization of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) in comparison to the conventional microporous TS-1 zeolite. This work provides some guidance for the development of a more efficient and greener seed-assisted synthesis method for hierarchical zeolites without the addition of any additional mesoporous/macroporous templating agent.
研究领域:
材料科学
·
催化化学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Weilong Hou,Kehang Lin,Xiangyu Zhang,Bowen Xu,Yuexia Wang,Xinqing Lu,Yijing Gao,Rui Ma,Yanghe Fu,Weidong Zhu
Nonoxidative propane dehydrogenation (PDH) has been regarded as an economic and efficient route to meet constantly increasing global demands for propylene. However, over industrially applied catalysts, thermally induced deactivation including coke formation and sintering of the active species occurs and simultaneously hydrocarbon cracking significantly reduces the selectivity for propylene. In the present work, titanosilicate-1 (TS-1) zeolite supported catalysts (Pt/TS-1) were developed for PDH. The results on the extensive characterizations of the prepared materials, in combination with density functional theory (DFT) calculations, verify that the framework Ti species in Pt/TS-1 can increase the dispersion and electron density of Pt, which significantly enhances the catalyst stability and selectivity for propylene. Utmost importantly, no sintering of the Pt active species in Pt/TS-1 occurs at the high temperatures required for the reaction and catalyst regeneration processes. Therefore, the current investigation provides a strategy for developing efficient PDH catalysts for practical applications.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2018
·
IF 4.521
Guojun Lv,Senlin Deng,Yi Zhai,Yongqiang Zhu,Haichao Li,Fumin Wang,Xubin Zhang
Hierarchical TS-1 stacked nanoplates with constrained mesopores were hydrothermally synthesized via a self-assembly process with the aid of P123 lamellar micelles. P123 lamellar micelles serve concomitantly as mesotemplate for hierarchical TS-1 zeolite and nanostructure regulator for TS-1 nanoplates. The successful preparation of TS-1 stacked nanoplates were verified by Scanning and Transmission electron microscope, X-ray diffraction patterns, FTIR spectra and UV–vis spectra. Moreover, their formation processes with crystallization time were investigated, and accordingly the possible mechanism was proposed. Hierarchical TS-1 stacked nanoplates displayed a chemical composition similar to that of hierarchical TS-1 zeolite with P123 spherical micelles as mesotemplate and showed remarkably enhanced catalytic activity in oxidative desulfurization of dibenzothiophene (DBT), 4,6-dimethyldibenzothiophene (4,6-DMDBT) and benzothiophene (BT) with tert-butyl hydroperoxide (TBHP) or hydrogen peroxide (H 2 O 2 ) as oxidant.
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 SOLID STATE CHEMISTRY
·
2021
·
IF 3.498
Hanfang Liu,Yu Wang,Tiantian Ye,Fupeng Wang,Saisai Ran,Huijie Xie,Jia Liu,Yichuan Li,Bin Li,Yanru Liu,Yongming Chai,Lei Wang
Nanosized titanium silicalite-1 (TS-1) demonstrates excellent catalytic ability in the selective catalytic oxidation reaction. However, their synthesis process is usually complicated with low yield under hydrothermal conditions, which is not in line with the concept of green chemistry. Herein, via fully utilizing untreated seeds solution, we report firstly an entirely green strategy for solvent-free synthesizing anatase-free nanosized TS-1 zeolite . The success lies in the fully utilization of seeds solution which is composed of supersaturated structure directing agent (TPAOH), unreacted silica source, water and formed MFI seeds (silicalite-1) without external purification. In the followed solvent-free synthesis of final nanosized TS-1 product, no additional TPAOH is added, which greatly reduces the synthesis cost and synthetic procedure and maintains a high product yield. The obtained nanosized TS-1 zeolite without anatase phase has high crystallinity , large specific surface area. More importantly, the nanosized TS-1 (Si/Ti = 77) catalysts exhibit excellent catalytic ability for the epoxidation of chloropropene with 40.0% conversion and 97.6% selectivity. This sustainable and green synthesis method opens up a new way to regulate nanosized zeolite.
研究领域:
材料科学
·
绿色化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2019
·Vol. 149
·期 9
·2586-2596
·
IF 2.372
Shen Xiaohua,Wang Jingjing,Liu Miaoqing,Li Mengzhe,Lu Jianjun
Abstract A new route to synthesis hierarchical Ti-rich TS-1 with uniform intracrystalline mesopores, uniform crystal size and the higher Ti content has been developed by using the environmental-friendly and cheap surfactant Triton X-100 as the assisted template agent and (NH 4 ) 2 CO 3 as crystallization-mediating agent. In this way, the surface area and pore volume of the resulting materials can be adjusted by the Triton X-100 content. The catalytic properties of the Nano-size hierarchical Ti-rich TS-1 were investigated by hydroxylation of benzene to phenol with H 2 O 2 as oxidizing agent and deionized water as solvent. Due to the combination of hierarchical pores and high titanium content, the hierarchical Ti-rich TS-1 shows improved catalytic activity in the oxidation of benzene. Graphical Abstract
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
ACS Omega
·
2020
·
IF 2.87
Yumeng Yang,Dan Gao,Rui Qian,Yuyang Jiang
Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) using conventional organic matrices for detection of small molecules has some limitations, such as heterogeneous analyte/matrix co-crystals, as well as interference of matrices in the low-molecular-weight range. In this work, a zeolite framework nanomaterial, TS-1, was applied as a MALDI matrix for the analysis of small molecules by MALDI-MS for the first time. To improve the signal intensity and reproducibility, TS-1 was modified with polydopamine (TS-1@PDA). Using TS-1@PDA as a matrix, organic substances in the low-molecular-weight region such as amino acids, nucleosides, peptides, oligosaccharides, and fatty acids can be detected by MALDI-MS in positive ion mode. Compared with traditional organic matrices like 2,5-dihydroxybenzoic acid (2,5-DHB) and α-cyano-4-hydroxycinnamic acid (CHCA), TS-1@PDA has the advantages including the formation of uniform sample spots, small background interference at low molecular weight, and better salt tolerance. Furthermore, this matrix was employed for the analysis of endogenous glucose in urine samples, and the level of glucose was quantified with a linear range of 0–10 mM (R2 > 0.98). The results demonstrated that TS-1@PDA has the potential to be used as an effective MALDI matrix for the analysis of small molecules in biological samples with excellent reproducibility and moderate sensitivity.
研究领域:
分析化学
·
生物医学
·
质谱技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2025
·
IF 3.5
Huanxu Teng,Meihua Zhu,Yixuan Shao,Siqi Shao,Qingsheng Wu,Ziming Li,Xiangshu Chen,Hidetoshi Kita
Supported TS-1 zeolites were successfully synthesized on α-Al 2 O 3 microsphere by secondary hydrothermal synthesis, which were placed in the fixed-bed reactor and catalyzed the oxidation of isopropanol(IPA) with hydrogen peroxide. Effects of synthesis parameters on the morphology and catalytic activity of the supported TS-1 zeolites were systematically studied in this work. Size of α-Al 2 O 3 microsphere, and crystallization temperature could determine the coverage, titanium coordination, and titanium content of the supported TS-1 zeolites. When the crystallization temperature and H 2 O/SiO 2 molar ratio of the initial synthesis solution were 150 °C and 120, the titanium-rich and anatase-free supported TS-1 zeolites were prepared on the ca. 1 mm α-Al 2 O 3 microsphere support. The supported TS-1 zeolites showed an excellent catalytic performance and stability for isopropanol oxidation, the isopropanol conversion and acetone selectivity reached 100 % within 2 h. Kinetic studies showed that the reaction conformed to the Langmuir-Hinshelwood mechanism and that the apparent activation energy was only 4.57 kJ/mol.
研究领域:
催化化学
·
材料化学
·
化学工程
·
多相催化
·
环境化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）