Nano Research
·
2023
·Vol. 16
·期 5
·6278-6289
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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
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2014
·
IF 4.058
C. Shen,Y.J. Wang,J.H. Xu,G.S. Luo
Porous glass supported with titanium silicalite (TS-1) particles were successfully prepared and used for oxidative desulfurization (ODS) of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT). Uniform-sized TS-1 particles were homogeneously dispersed on the surface of the porous glass beads. Effects of reaction duration, catalyst content, initial concentration, oxidant amount, and temperature on conversions were investigated. The prepared catalysts showed excellent catalytic performance. The optimal mole ratio of oxidant-to-DBT was 10 or 15. Complete conversion was obtained within 3 min at 343 K using catalyst with Ti content of 0.507 wt.%. Compared with other studies, the space–time yield was increased by one order of magnitude without any addition of solvent or metal nanoparticles. Experimental results and computer simulations revealed that the coordinated state of Ti species has a key role in the catalytic activity. Spent catalyst would be regenerated by heating at high temperature, no decrease was observed in catalytic activity after three cycles.
研究领域:
化学工程
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催化材料
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2025
·
IF 3.9
Rui Feng,Zhou Fang,Runxi Zhang,Xiaoyan Hu,Tianbo Li,Wei Zhou,Feifei Yang,Xinlong Yan,Shijian Lu
Direct hydroxylation of benzene to phenol is a more environmentally friendly way to generate phenol compared with the traditional method. This study developed vanadium-modified hollow-structured titanium silicate-1 (TS-1) as a catalyst for the effective hydroxylation of benzene to phenol under moderate conditions using hydrogen peroxide as an oxidant. The synthesis of TS-1 zeolites has been improved using traditional hydrothermal, crystal seed, and dissolution–recrystallization techniques. Compared with conventional TS-1, hollow-structured TS-1 exhibited a higher mesopore volume and surface area. Later, vanadium doping increased the charge density associated with the framework Ti centers and acid site content. In the radical reaction process, the adsorption and activation of benzene on highly reactive Ti–OOH intermediates, as well as the improvement of performances toward benzene hydroxylation to phenol, were facilitated by the increase in the concentration of open active centers and acid and electron characteristics.
研究领域:
催化化学
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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
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
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2013
·
IF 3.473
C. Shen,Y.J. Wang,C. Dong,G.S. Luo
In this work, porous glass beads supported with TS-1 particles have been successfully prepared through in situ crystallization. TS-1 particles with uniform size and high crystallization are well dispersed on the surface of porous glass beads. As the support, porous glass beads exhibit the advantages of more manageable surface chemistry, better chemical and thermal stability, and larger specific surface area compared to that of conventional TS-1 films on flat or tubular supports. The experimental results show that the surface chemistry has profound influence on the morphology of TS-1 particles. The catalytic performance of the material was characterized with the reaction of ammoximation of cyclohexanone. Complete conversion was reached after 20 min in a stirred tank reactor with the selectivity of 100%. Compared with the commercial catalyst, the reaction rate was increased by 54 times. The prepared catalysts were packed in a bed reactor, and the effects of space time, content of catalyst, temperature and pressure were investigated. The conversion of 48.1% was reached by the catalyst with TS-1 loading of 0.183 wt.% at 353 K and the space time of only 1.57 min, and 100% recovery in catalytic activity after 5 cycles was demonstrated.
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
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2024
·
IF 5.8
Haihan Huang,Jie Zheng,Kaiyue Wu,Jian Lin,Xin Lin,Quan Yao,Qianyu Fan,Dechao Wang,Yuanbo Huang,Jianchun Jiang,Zhifeng Zheng
Catalytic pyrolysis technology is one of the most environmental and efficient approach in converting biomass waste into high-value chemicals and fuels. In this study, the ex-situ catalytic pyrolysis of cellulose to produce furans and olefins was reported using various metal-loaded TS-1 as catalysts. The experimental results showed that the Au/TS-1 exhibited an exceptional catalytic activity in the production of furans and olefins, achieving a selectivity of 49.17 % and 40.65 %, respectively. Ni/TS-1 effectively promoted the formation of ethylene, yielding a selectivity of 97.49 % and a yield of 6.11 C-mol%. Under the optimized conditions: pyrolysis temperature of 550 ℃, catalytic temperature of 600 ℃, and catalyst to cellulose mass ratio of 20:1, the Au/TS-1 catalyst achieved a furans selectivity of 41.91 % with a yield of 11.94 C-mol%, while olefins selectivity and yield were 49.84 % and 18.99 C-mol%, respectively. At this condition, Au/TS-1 still has excellent catalytic activity after 10 cycles and has good catalytic effect towards different biomass feedstocks. Furthermore, the possible mechanism to produce furans and olefins was revealed. This research offers valuable insights for guiding the directed conversion of biomass into value-added chemicals, paving the way for a more sustainable future.
研究领域:
化学工程
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催化
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生物质转化
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可再生能源
✓ 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
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催化化学
·
合成化学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2019
·
IF 4.888
Hongxia Chen,Runduo Zhang,Wenjing Bao,Hao Wang,Zhoujun Wang,Ying Wei
The catalytic removal of HCHO with low noble-metal loading at room temperature is meaningful and challenging work. Herein, high performance catalysts x Pt/TS-1 (Si/Ti = 30, x = 0.1, 0.3, and 0.6 wt%) for HCHO oxidation were synthesized by polyvinyl alcohol-protected NaBH 4 reduction method. The Pt/TS-1 sample loading with 0.3 wt% Pt nanoparticles (NPs) could completely remove 120 ppm HCHO at space velocity (SV) of 60,000 mL/(g h) at 20 °C. Moreover, the 0.3Pt/TS-1 sample remained outstanding activity and stability in humid air with 35–75% water vapor and at high SV with a range between 60,000 and 240,000 mL/(g h). Based on the results of UV–vis, Raman, NH 3 -TPD, Contact angle measurement, CO chemisorption , and O 2 -TPD, the excellent catalytic performance of Pt/TS-1 was mostly attributed to high Pt dispersion and high concentration of adsorbed oxygen species. This work expands the field of utilization of zeolite supported noble-metal catalysts for the purification of indoor pollutants.
研究领域:
环境科学
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催化化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 2
·1015-1020
·
IF 3.119
Xing Wei,Yu-Jia Wang,Tie-Qiang Ren,Hai-Yan Wang,Min Wei
Hydrothermal synthesis is a typical method for the preparation of TS-1. In the current study, agitation was introduced during the crystallisation stage, and nano-sized TS-1 with little anatase TiO2 was successfully synthesised in a short time (1–8 h). Furthermore, under rotational crystallisation conditions, a series of TS-1 samples was prepared with different crystallisation times, and the products obtained were investigated as catalysts for the oxidative desulfurisation of thiophene from a model fuel. All samples were characterised utilising X-ray diffraction (XRD), scanning electron microscopy (SEM), N2-adsorption, ultraviolet-visible (UV-Vis) spectroscopy and Fourier-transform infrared (FT-IR) spectroscopy techniques. It was found that under rotational crystallisation conditions, nano-sized TS-1 could be synthesised in a short time that had improved efficiency for the oxidative desulfurisation reaction of thiophene in comparison with TS-1 synthesised by static crystallisation for 24 h.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Guojun Lv,Tao Wang,Yan Chen,Jiangzhang Wang,Xuyang Zou,Jun Lu,Fumin Wang,Xubin Zhang,Yi Zhai
Design of catalyst particles bearing excellent diffusion performance and suitable surface wettability is of great importance to the successful application of Pickering interfacial catalysis. In this study, selective oxidation reactions over hydrophobized hollow TS-1 zeolite were applied as probe reactions to investigate the influence of catalyst diffusion performance closely related to mesopore size on its catalytic activity. Hydrophobized hollow TS-1 zeolite particles were prepared via a post desilication treatment accompanied with precrystallization treatment. The synthesized hydrophobized hollow TS-1 zeolite was characterized by Scanning electron microscopy, Transmission electron microscopy , X-ray diffraction, UV–vis absorption spectrometry , Fourier-transform infrared spectroscopy and Nitrogen adsorption-desorption. Stable Pickering emulsions including 1-hexene-hydrogen peroxide, cyclohexene-hydrogen peroxide and cyclohexanone-water were prepared with hydrophobized hollow TS-1 zeolite particles as emulsifier . HTS-1–393(2)-S zeolite synthesized with precrystallization at 393 K for 2 h presented the maximum values of 43.9 mol/(Ti-mol·h) for 1-hexene epoxidation , 15.7 mol/(Ti-mol·h) for cyclohexene epoxidation and 247.3 mol/(Ti-mol·h) for cyclohexanone ammoximation. In addition, HTS-1–393(2)-S zeolite particles displayed good reusability for more than five cycles.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2021
·
IF 5.062
Mengzhe Li,Xiaohua Shen,Miaoqing Liu,Jianjun Lu
L-lysine is used as a crystallization regulator, and a two-step synthesis method is adopted in a concentrated gel system, which provides a new route to synthesize of nano-sized TS-1 zeolite. The new synthesis strategy was used to successfully synthesize TS-1 zeolite with a particle size less than 100 nm. The rate of crystal nucleation is faster than the crystal growth at the low temperature in the first step. Introduction of L-lysine can prevent crystal growth to form nano-sized TS-1 zeolite at the high temperature in the second step. Meanwhile, L-lysine decrease the pH value of the gel system, which is favorable for Ti atoms to incorporate the TS-1 framework. TS-1 nanozeolite can effectively reduce the diffusion resistance, and nanozeolite has a large specific surface area and high stability. Therefore, TS-1 nanozeolite exhibits the excellent catalytic performance during the hydroxylation of benzene. The conversion of benzene has been greatly improved and the types of by-products are effectively reduced. The conversion of benzene reached 50.2%, and the yield of phenol was 30.8% without by-product benzoquinone. TS-1 nano-zeolite as a catalyst for benzene hydroxylation shows great potential in industrial application.
研究领域:
化学工程
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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
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Haonan Zhang,Changhe Lu,Shuai Wang,Qinhua Zhang,Qiang Zhou,Shuxu Zhu,Chong Qi,Mingbo Wu,Wenting Wu
The utilization of O 2 for propylene epoxidation is a highly desirable reaction due to its 100 % atom economy. However, achieving this reaction under mild conditions presents a significant challenge. In this paper, we present a tandem reaction system that combines 4,4′-dibromobenzophenone (BP) modified carbon nitride (g-C 3 N 4 ) with titanium silicalite zeolite (TS-1) to enable the selective photooxidation of propylene into propylene oxide at room temperature, using O 2 as the oxygen source. The achieved production rate of propylene oxide was an impressive 1195 μmol/g cat. /h, with a selectivity exceeding 99 %. Furthermore, the catalyst exhibited no significant deactivation after 5 cycles. Spectra and in-situ capture experiments revealed that the reaction involved a two-step system, with photocatalytic production of H 2 O 2 and propylene epoxidation facilitated by H 2 O 2 ·H 2 O 2 was generated through O 2− and 1 O 2 pathways, with an in-situ utilization efficiency of H 2 O 2 reaching 82 %. This work presents a novel approach for the direct epoxidation of propylene using O 2 .
研究领域:
化学工程
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环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
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