INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Hang Li,Yi Zhai,Xubin Zhang,Guojun Lv,Yu Shen,Xuqing Wang,Tao Jiang,Yuzhou Wu
Hierarchical iron-containing TS-1 zeolites (FTS) were successfully synthesized via post-treatment desilication over microporous Fe-TS-1, which were prepared through a one-step hydrothermal synthesis. The prepared samples were characterized by X-ray diffraction, N2 adsorption–desorption, field-emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, ultraviolet visible spectroscopy, and X-ray fluorescence spectrometry. The experimental results illustrated that the MFI structure of all the FTS samples remained unchanged after NaOH desilication and acid treatment. The newly created mesopores can be controlled by changing the amount of framework Fe, as the extraction of Si could be affected because of the inhibitory effect of iron species during the desilication process. The catalytic performance of the prepared samples in phenol hydroxylation with H2O2 was investigated. Among all the samples, FTS-50-D showed a highest phenol conversion of 45.2% and a dihydroxybenzene selectivity of 95.2%. Besides, FTS-50-D also showed good reusability for five recycling tests.
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
CHEMICAL ENGINEERING SCIENCE
·
2022
·
IF 4.889
Chenyang Zhao,Hongwei Zhu,Yujia Liu,Junjie Feng,Xiang Feng,Wei Xu,Zhe Yang,Bing Sun
The direct epoxidation of propylene has been a hot topic in the academic field for years. Researchers have spent extensive effort on the development of catalyst, however, only limited attention on the effect of reaction conditions, especially pressure. In this paper, we found for the first time that elevated pressure should favor the forward epoxidation reaction, it actually led to a drop of reaction rate in this system. We proposed explanation by considering the difficulty of gas molecules diffusing into and out of the micropores on the TS-1 zeolite surface. Higher pressure would inhibit the escaping of the gas molecules from the micropores and lead to carbon deposition inside the channel. To validate this hypothesis, we designed and compared catalysts with micropores blocked (BTS-1) and unblocked (TS-1) and found that the BTS-1 showed higher resistance to pressure change and significantly longer life time than the TS-1.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Fei Fan,Shiyu Han,Ying Li,Lu Qi,Jie Kang,Zhiping Chen,Chang Tian,DeChao Wang,Wenwu Zhou
The microenvironments including the surface hydroxyls , the oxygen vacancies , and the d-band center of hierarchical TS-1 zeolite pickled by hydrochloric acid were regulated by ZrO 2 , the effect of ZrO 2 on the physicochemical properties and the catalytic performances of the corresponding NiMoS supported catalysts were studied. The experimental and theoretical calculation results show that the d-band center, the surface hydroxyl groups , and the oxygen vacancies were regulated after incorporation of ZrO 2 . Resulting in the modulated acidity of the support and the metal support interaction of the catalysts, further promoting the formation of type-II NiMoS active phases. The catalytic performance evaluations show that catalyst NiMo/1-ZAT exhibits the superior HDS performance, kinetic study further demonstrated that the enhanced catalytic activity was mainly contributed by the improved direct desulfurization activity generated from the moderate support acidity, suitable MSI, highest sulfidation degrees, most type-II NiMoS active phase and highest activity of individual active sites.
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
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
MICROPOROUS AND MESOPOROUS MATERIALS
·
2025
·
IF 4.7
Beining Luo,Yan Wang,Yingqi Zhang,Caifeng Qiu,Guoqiang Yu,Liang Li,Xianzai Yan,Guoqiang Wu
Catalytic epoxidation limitations of conventional ellipsoid titanosilicate-1 (TS-1) remains owing to the narrow microporous channels and low efficiency of the Ti species. Herein, two-dimensional planer TS-1 zeolite (TS-1-P) was synthesized by adding crystal growth regulator in the hydrothermal synthesis process, and then TS-1-P supported molybdenum (Mo/TS-1-P) and mesoporous Mo/TS-1-P (Mo/MTS-1-P) were prepared and applied in epoxidation of olefins. The TS-1-P and the modified TS-1-P catalysts show a similar MFI framework and grain morphology but the different pore structure and coordination environment of Ti or Mo species. Especially, the Mo/MTS-1-P possesses many mesoporous pore and highly dispersed Mo species, which can improve the coordination environment of Ti species and weaken the Ti-O bond, the results are beneficial for the framework Ti species to combine more easily with H 2 O 2 to C=C band of the olefin molecules. Therefore, compared with TS-1-P, Mo/MTS-1-P exhibits the highest conversion of ACH (91.78 %) and 1-hexene (47.44 %) in the epoxidation of ACH and 1-hexene, respectively, the selectivity of epoxidized products simultaneous is above 96.42 % and 94.04 %, respectively. Moreover, the deactivation behavior of carbon deposit on the catalyst surface and regeneration method were also proposed. The successful preparation of Mo/MTS-1-P not only results in an efficient catalyst for epoxidation process but also provides a possible approach for surface and pore structure modification of TS-1 zeolite.
研究领域:
催化化学
·
材料科学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2022
·
IF 5.876
Xiu Gao,Yingqi Zhang,Yanping Hong,Beining Luo,Xianzai Yan,Guoqiang Wu
Methyl oleate (MO) macromolecules are unable to access the microporous channel of conventional titanium silicalite-1 (TS-1) zeolite , which leads to the low catalytic activity of epoxidation of MO. Herein, the small-size TS-1 (TS-1-s) zeolite with a large surface area was synthesized successfully through steam-assisted crystallization, and then a novel blocked TS-1-s supported molybdenum (Mo/TS-1-bs) catalysts were prepared for efficient epoxidation of MO with clean H 2 O 2 to produce epoxidized methyl oleate (EMO). Various characterization results show the introduced Mo species are highly dispersed on the outer surface of TS-1-s without destroying the structure of the MFI type zeolite and the tetrahedral framework titanium (Ti 4+ ). Interestingly, a large number of Mo 6+ species exhibit certain epoxidation activity attributing to the generating of electrophilic molybdenum hydroperoxide (Mo–OOH) species via Mo species combined with H 2 O 2 , which could adsorb and react easily with MO molecules. Furthermore, the Mo species are also coordinated with Ti 4+ species through the O atom resulting in the facile attack of the Ti–O bonds by H 2 O 2 and easy to form an active intermediate. Therefore, compared with the conventional TS-1, the Mo/TS-1-bs shows higher catalytic activity in the epoxidation reaction. However, the acidity of Mo/TS-1-bs catalysts increases with increasing the Mo-loading owing to the formation of Lewis acid, which leads to the side reactions and the decrease of EMO selectivity. As a consequence, the efficient, non-corrosive and green catalytic system for epoxidation of MO was developed, and the activity improvement of Mo species and the influence of acid were also demonstrated.
研究领域:
催化化学
·
材料科学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Sustainability
·
2024
·
IF 7.1
Weijiong Dai,Jing Zhao,Zongqiang Liu,Yan Wang,Jiajun Zheng,Ruifeng Li
Plate-like TS-1 zeolites offering a short diffusion pathway along the b- axis are highly desirable catalysts in the reaction of alkene epoxidation. Herein, we successfully developed a simple synthetic strategy toward reducing the thickness along the b -axis of TS-1 zeolite crystals, l -lysine adopted as a zeolite growth modifier was firstly proposed to prepare plate-like TS-1 zeolite. Meanwhile, through tuning the preliminary aging time, plate-like TS-1 zeolites with thickness in the range of 80–1000 nm can be controllable obtained. In this work, the synthesis parameters controlling the formation of plate-like TS-1 zeolites are studied, and the factors controlling the zeolite growth were well elucidated. Compared with the conventional TS-1 zeolite as well as the plate-like TS-1 synthesized in the fluoride-containing medium, the obtained plate-like TS-1 shows improved catalytic performances in catalyzing epoxidation of 1-hexene.
研究领域:
材料科学
·
催化化学
·
合成化学
✓ 已验证
产品关联
DOI
高影响因子
Nano Research
·
2023
·Vol. 16
·期 5
·6278-6289
·
IF 9.9
Xu Jialun,Zhang Zhihua,Yu Daiyi,Du Wei,Song Nan,Duan Xuezhi,Zhou Xinggui
The catalytic performances over propylene epoxidation with H 2 and O 2 (HOPO process) are significantly affected by the properties (e.g., surface properties, Ti coordination, and morphology) of titanosilicate zeolite. Introducing urea into zeolite synthesis is a simple and convenient method to modify these properties of titanosilicate zeolite. Uncalcined pore-blocked titanium silicalite-1 (TS-1, i.e., TS-1-B) with the lower urea dosage possesses more defective structure and unsaturated coordinated Ti sites verified by 29 Si nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS) analysis, which results in a high initial activity and hydrogen efficiency; while the high surface acidity generated by these Ti species leads to a continuous decrease in the activity and the propylene oxide (PO) selectivity during the reaction. As the amount of urea gradually increases, the TS-1-B samples present the reduced surface defects and defective and unsaturated Ti species. Specially, TS-1-B-0.30U presents the weaker PO adsorption on PO-diffusion reflectance infrared Fourier transform spectra (DRIFTS), and thus results in the high stable PO formation rate and selectivity over its Au catalyst. Furthermore, a flat-plate-like shape with a shorter thickness of 100 nm along the b-axis direction is observed on the urea-modified TS-1. Compared with the conventional ellipsoidal TS-1 with crystal sizes of 200 and 500 nm, the flat-plate-like TS-1-0.30U displays the less surface defects, unsaturated Ti species, and the weaker Lewis acid, which is favorable for the desorption and intracrystalline diffusion of PO, thus reduces the occurrence of side reactions for the improved selectivity and stability. This work may provide a reference for developing titanium-containing materials with high activity and stability over HOPO reaction.
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
CRYSTAL GROWTH & DESIGN
·
2023
·
IF 3.8
Zhenyuan Yang,Yanan Guan,Lei Xu,Yangtao Zhou,Xiaolei Fan,Yilai Jiao
This work presents the development and systematic study of a method to prepare hierarchical titanium silicalite-1 (TS-1) zeolites with high tetra-coordinated framework Ti species content. The new method involves (i) the synthesis of the aged dry gel by treating the zeolite precursor at 90 °C for 24 h; and (ii) the synthesis of hierarchical TS-1 by treating the aged dry gel using tetrapropylammonium hydroxide (TPAOH) solution under hydrothermal conditions. Systematic studies were conducted to understand the effect of the synthesis conditions (including the TPAOH concentration, liquid-to-solid ratio, and treatment time) on the physiochemical properties of the resulting TS-1 zeolites, and the results showed that the condition of a TPAOH concentration of 0.1 M, liquid-to-solid ratio of 1.0, and treatment time of 9 h was ideal to enable the synthesis of hierarchical TS-1 with a Si/Ti ratio of 44. Importantly, the aged dry gel was beneficial to the quick crystallization of zeolite and assembly of nanosized TS-1 crystals with a hierarchical structure (Sext = 315 m2 g–1 and Vmeso = 0.70 cm3 g–1, respectively) and high framework Ti Species content, making the accessible active sites ready for promoting oxidation catalysis.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2024
·
IF 4.7
Mengqi Wang,Bo Chen,Yan He,Zhili Li,Yuanyuan Ge
Titanium silicalite-1 zeolite (TS-1) has been widely used as a catalyst for the epoxidation of 1-hexene. However, fast synthesis of TS-1 with high activity and stability remains a great challenge. In this study, a new strategy using sodium persulfate (SPS) as a crystallization modifier was proposed for the accelerated synthesis of anatase-free TS-1. The anatase-free TS-1 (TS-20-SPS) could be obtained after 20 h of hydrothermal crystallization. TS-20-SPS had a low Si/Ti ratio (31) and achieved a high conversion (20 %) in the epoxidation of 1-hexene at room temperature (298 K), which was 200 % higher than that of TS-1 synthesized without adding SPS. The addition of SPS not only accelerated the crystallization due to the generation of ·OH, but also reduced the pH value of the system to avoid the generation of anatase. This SPS-assisted approach offers an avenue for the accelerated synthesis of high-performance, anatase-free TS-1.
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
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
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2018
·
IF 3.649
Qi Du,Yiping Guo,Pei Wu,Hezhou Liu
Hierarchically porous TS-1 (HTS-1) zeolite with nanocrystal aggregate structure has been successfully synthesized by hydrothermal and steam-assisted crystallization (SAC) method with the aid of polyvinyl alcohol (PVA). It has been found that the formation of mesoporous aggregates was attributed to the construction of PVA three-dimensional network. The mesoporous aggregate structure could be well maintained by SAC method, resulting in HTS-1 with either surface titanium enrichment or highly interconnected mesopores and high external surface. Both could contribute to the excellent catalytic performance of HTS-1 in oxidative desulfurization of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT). The TOF numbers of HTS-1 reached a very high value to 114.9 h −1 and 53.2 h −1 in the oxidation of DBT and 4,6-DMDBT, respectively. Moreover, the HTS-1 showed good stability and remained ∼90% of its initial activity even after 3 times cycle. The high catalytic activity and good stability suggest that HTS-1 is a promising catalyst for deep oxidative desulfurization.
研究领域:
催化化学
·
材料科学
·
环境化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）