MATERIALS CHEMISTRY AND PHYSICS
·
2022
·
IF 4.778
Xiaomei Yang,Xu Chen,Bin Lv,Yunlai Su,Lipeng Zhou
Sn-Beta zeolite is an excellent catalyst for the transformation of biomass derived carbohydrates. However, the long synthesis time restricted its application. Here, alkaline (earth) salt was used as promoter to accelerate the crystallization of Sn-Beta. Different alkaline (earth) salts and the amount of MgCl 2 were investigated. The properties of the synthesized samples were characterized by various techniques and compared with Sn-Beta, and the catalytic performance was investigated for the conversion of glucose to methyl lactate (MLA). The results indicate that a small amount of alkaline (earth) salt, especially MgCl 2 , promoted dramatically the crystallization of Sn-Beta. The full crystallization time was shortened from 15 d to 5 d with the aid of MgCl 2 ( n Mg / n Sn of 1.0) for Sn-Beta with n Si / n Sn of 100. Sn 4+ cations were incorporated into the framework sites, while Mg 2+ cations replaced the protons of silanol defects. Mg–Sn-Beta with strong Lewis acid sites and less silanols showed high activity and selectivity for glucose conversion to MLA. The yield of MLA is 20% over the fully crystallized Sn-Beta at 120 °C for 15 h and glucose concentration of 3.1 wt%, which increased significantly to 44% over the fully crystallized 1 Mg–Sn-Beta. Furthermore, Mg–Sn-Beta is stable and recyclable.
研究领域:
催化化学
·
生物质转化
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Xiaolong Liu,Jiahe Sun,Shuo Li,Kaixuan Yang,Ting Su,Hongying Lü,Zhiguo Zhu
Sn-containing zeolite catalysts exhibit the unique feature of selectively activating carbonyl groups in organic compounds, which demonstrate relatively high activity and selectivity in the Baeyer-Villiger (B V) oxidation of aldehydes or ketones using H 2 O 2 as the oxidant. However, the influence of diffusion property and trace water on the ε-caprolactone selectivity as targeted product in the cyclohexanone's B V oxidation system with the green oxidant of aqueous H 2 O 2 remains unclear. To address this, three kinds of Sn-Beta zeolites are prepared by interzeolite transformation, structural reconstruction, and post-synthesis method to establish structure-property relationships. The physicochemical property and Sn coordinated state are investigated in detail. The existence of trace water in the reaction system negatively affects the conversion and product selectivity by competitive adsorption of water with reaction substrates and facilitated hydrolysis of ε-caprolactone, respectively. DFT calculation implies that kinetics dominates the conversion of cyclohexanone → ε-caprolactone → 6-hydroxycaproic acid. The structure-property relationship indicates that the cyclohexanone conversion and ε-caprolactone selectivity are closely related to the adsorption amounts of substrates and the diffusion performance of products, respectively, over Sn-Beta zeolite catalysts. Finally, the reusability and deactivation mechanism are analyzed. This study aims to provide guidance for designing efficient stannosilicate zeolite catalysts for B V oxidation through precisely modulating the zeolite's diffusion property.
研究领域:
催化化学
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材料科学
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有机化学
✓ 已验证
产品关联
DOI
高影响因子
Reaction Chemistry & Engineering
·
2024
·
IF 3.4
Yongming Xu,Wenzhao Liu,Bo Xu,Ke Wang,Jinchu Yang,Yueqi Si,Xuebin Zhao,Tingting Zhang,Zhan Zhang,Xueyi Qiao,Tianliang Lu
Glycolic acid finds extensive applications in the production of biodegradable polymers, pharmaceuticals, and fine chemicals. In this study, a Pt catalyst supported on the Sn-Beta zeolite (Pt/Sn-Beta) was developed to achieve the efficient and highly selective catalytic oxidation of ethylene glycol with molecular oxygen to prepare glycolic acid at near-room temperature (30 °C). Characterization results, including XRD, TEM, XPS, FT-IR, and O2-TPD, revealed that the relatively uniform dispersion of Pt particles, the optimal density of Lewis and Brønsted acid sites in the catalyst, and the synergistic interaction between Sn and Pt sites might be key factors contributing to the excellent catalytic performance of the Pt/Sn-Beta catalyst. By optimizing the reaction conditions, a 90% conversion of ethylene glycol and an 81% selectivity of glycolic acid were obtained. Furthermore, Pt/Sn-Beta exhibited excellent stability, with no significant decrease in catalytic performance after six repeated uses.
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
ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Bo Tang,Shuang Li,Wei-Chao Song,En-Cui Yang,Xiao-Jun Zhao,Naijia Guan,Landong Li
In this work, BEA-type hierarchically structured stannosilicate zeolite Sn-Beta-H was developed, which involved alkali-induced degradation of all-silica Beta (Si-Beta) and self-assembly of the resultant Si-Beta fragments with SnCl2·2H2O in the hydrothermal condition templated with tetraethylammonium hydroxide (TEAOH) and polydiallydimethylammonium chloride (PDADMAC). The synthesized Sn-Beta-H zeolite was comprehensively characterized by means of XRD, N2 physisorption, TEM, UV–vis, XPS, TG, DRIFT, and FTIR spectroscopy with pyridine and deuterated acetonitrile adsorption. The Lewis acidity related to isolated tetrahedrally coordinated Sn species in the hierarchical porous Beta framework was revealed, which existed in the form of partially hydrolyzed and framework-integrated species. The Sn-Beta-H zeolite worked efficiently in the catalytic transformation of a series of carbohydrates into methyl lactate, outperforming the microporous Sn-Beta and postsynthesized mesoporous meso-Sn-Beta counterparts. The influence parameters such as mesoporosity, hydrophilicity/hydrophobicity, and Lewis acidity on the glucose conversion were studied in detail.
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
FUEL
·
2022
·
IF 8.035
Tianliang Lu,Xianfeng You,Yanlong Zong,Yongming Xu,Xiaomei Yang,Lipeng Zhou
Production of γ-valerolactone (GVL) from ethyl levulinate (EL) was studied by catalytic transfer hydrogenation (CTH) strategy under mild conditions. Hydrothermally synthesized Sn-Beta zeolites with high crystallinity show high catalytic activity and selectivity. With isopropanol as hydrogen source, 97.1 % GVL yield with 100 % selectivity was given under 110 °C. Crystallization time for synthesis of Sn-Beta showed great effect on the catalytic performance. Sn-Beta- x d catalysts with longer crystallization time (≥7 days) have high crystallinity and better catalytic performance. Firstly, longer crystallization time is necessary for the formation of large amount of Lewis acid sites which catalyze the conversion of EL to GVL. Secondly, high level of silanol groups in Sn-Beta has negative effect on the catalytic performance. High crystallinity means the amount of silanol groups in Sn-Beta- x d at a low level which is favorable for this CTH reaction. Meanwhile, this is why hydrothermally synthesized Sn-Beta shows higher catalytic activity than post-synthesized Sn-Beta in the conversion of EL to GVL. Furthermore, the catalyst was reusable.
研究领域:
化学工程
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2019
·
IF 4.182
Qingrun Meng,Jiaxu Liu,Guang Xiong,Xinyao Li,Liping Liu,Hongchen Guo
The Sn-Beta zeolite is an efficient Lewis acid catalyst for a wide range of chemical reactions. Here a seed-free aerosol-assisted hydrothermal strategy is used to synthesize plate-like Sn-Beta zeolite with higher tin content. A majority of Sn species were transformed into the framework of Beta zeolite as the desired tetrahedral coordination state, which creates strong Lewis acid sites. Moreover, the diffusion property of the Sn-Beta zeolite can be further improved by a mild base-surfactant (NH 3 ˙ H 2 O-CTAB) treatment. The addition of CTAB can not only narrow the mesopore distribution but also prevent the excessive loss of Sn species. The obtained hierarchical Sn-Beta zeolite exhibits an enhanced catalytic performance in the Baeyer–Villiger oxidation of bulky ketone.
研究领域:
催化材料
·
化学工程
·
纳米材料合成
✓ 已验证
DOI
高影响因子
CELLULOSE
·
2025
·
IF 4.8
Jin Mengyu,Wu Detong,Song Yuanbo,Shi Yang,Wang Xiaoxia,Shen Zheng,Zhang Yalei
This study presents an efficient strategy for converting high-boiling solvent (HBS) pretreated cellulose into lactic acid (LA) over a Cr-Sn-Beta bimetallic catalyst synthesized by flash Joule heating (FJH). Ethylene glycol-based HBS pretreatment effectively enriched cellulose content in straw, while the FJH method enabled rapid and uniform metal incorporation. The resulting Cr-Sn-Beta catalyst exhibited a maximum LA yield of 33.54% with a carbon balance of 90.08%, showing high selectivity and catalytic efficiency. The synergistic function of Cr and Sn acid sites was also evaluated. This work provides a promising route for biomass valorization and catalyst design via combined pretreatment and advanced synthesis techniques.
研究领域:
催化
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生物质转化
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2020
·Vol. 10
·期 24
·8437-8444
·
IF 5.721
Xiaomei Yang,Liuyong Wang,Tianliang Lu,Beibei Gao,Yunlai Su,Lipeng Zhou
Hydrothermally synthesized Sn-Beta is an excellent catalyst for the conversion of sugars to alkyl lactates. However, its catalytic performance is highly dependent on the synthesis parameters. In this work, the effects of the synthesis parameters such as the water amount of the synthesis gel and the crystallization time on the synthesis and properties and catalytic performance of Sn-Beta in the conversion of glucose to methyl lactate (MLA) were investigated. The crystallization rate was accelerated remarkably by reducing the water amount of the synthesis gel. With the aid of the Si-Beta seed, Sn-Beta was almost fully-crystallized after one day with nH2O/nSiO2 of 4.5, but seven days were needed with nH2O/nSiO2 of 7.5. However, Sn-Beta synthesized with nH2O/nSiO2 of 4.5 has more extraframework SnO2 due to the fast formation of the *BEA structure and the slow incorporation of Sn4+ into the framework sites, which resulted in the lower activity of MLA formation. More Sn4+ species were incorporated into the framework sites and thus more Lewis acid sites were generated with increasing crystallization time. At the same time, the ratio of open to closed Sn sites (RO/C) increased, which led to the decrease in the activity of MLA formation and due to that, the open Sn site with a proximal silanol is unfavorable for the conversion of glucose to MLA. During recycling study, it is surprisingly found that the yield of MLA increased gradually over the fully-crystallized Sn-Beta catalyst. Characterization results of the recovered catalyst from the eighth run indicate that the structure was preserved well, but the value of RO/C reduced due to the change of the state and microenvironment of Sn species.
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
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Weiping Liao,Haoyi Lin,Jiaxing Zhang,Jiaqi Wang,Kaixuan Yang,Ting Su,Hongying Lü,Zhiguo Zhu
2,5-Furandicarboxylic acid (FDCA) is a potential substitute of petroleum-based terephthalic acid to manufacture polymer. The selective aerobic oxidation of renewable 5-hydroxymethylfurfural (HMF) to FDCA is a promising and appealing route for establishing sustainable and environmentally friendly chemical process. Au catalysts have exhibited exceptional catalytic performances for this highly anticipated chemical transformation, where the used support intensively impacts the catalytic productivity from the standpoint of metal-support and guest organic-support interactions. Herein, Sn-Beta zeolite was straightforward and rapidly synthesized via structural reconstruction without the auxiliary of any solvents, which was adopted as support for Au catalyst to construct bifunctional catalysts. As for Au/Sn-Beta sample, Lewis acid sites were related to Sn 4+ ions in the zeolite framework, while electronic properties and particle size of Au species were capable of being modulated by Au dosages. In addition, charge transfer from Au species to framework Sn 4+ ions resulted in the formation of Au δ+ species. Au/Sn-Beta catalyst with metal-Lewis acid cooperative active sites showed unique catalytic productivity of FDCA product in the aerobic oxidation of HMF to FDCA, whose catalytic performance was correlated with Lewis acid amounts as well as geometric and electronic effect of Au particle. Reaction mechanism analysis revealed the pathway and concrete step that Lewis acid site functioned. The aim is to provide some guidance for constructing a task-specific multifunctional supported catalyst from the view of support-enhanced effect for the catalytic conversion of biomass resource with multi-functional-groups.
研究领域:
催化化学
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材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Scientific Reports
·
2016
·Vol. 6
·期 1
·1-8
·
IF 5.228
Dong Wenjie,Shen Zheng,Peng Boyu,Gu Minyan,Zhou Xuefei,Xiang Bo,Zhang Yalei
Lactic acid is an important platform molecule in the synthesis of a wide range of chemicals. However, in aqueous solutions without alkali, its efficient preparation via the direct catalysis of sugars is hindered by a side dehydration reaction to 5-hydroxymethylfurfural due to Brønsted acid, which originates from organic acids. Herein, we report that a previously unappreciated combination of common two metal mixed catalyst (Zn-Sn-Beta) prepared via solid-state ion exchange synergistically promoted this reaction. In water without a base, a conversion exceeding 99% for sucrose with a lactic acid yield of 54% was achieved within 2 hours at 190 °C under ambient air pressure. Studies of the acid and base properties of the Zn-Sn-Beta zeolite suggest that the introduction of Zn into the Sn-Beta zeolite sequentially enhanced both the Lewis acid and base sites and the base sites inhibited a series of side reactions related to fructose dehydration to 5-hydroxymethylfurfural and its subsequent decomposition.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2019
·
IF 4.63
Zhiguo Zhu,Haikuo Ma,Mingtong Li,Ting Su,Hongying Lü
Sn-containing Beta (Sn-Beta) zeolite is extensively applied in industrially-relevant reactions as a highly active and robust Lewis acid heterogeneous catalyst. Nonetheless, environmentally-unfriendly fluoride is generally required to the directly hydrothermal synthesis of Sn-Beta. In this work, an innovative strategy of interzeolite transformation with steam-assisted conversion is provided to directly synthesize Sn-Beta zeolite in the absence of fluoride. Silica source of FAU and steam-assisted conversion were two necessary factors for the successful synthesis of Sn-Beta zeolite. It was found that highly crystallized Sn-Beta zeolite with isolated framework Sn ions was hydrothermally synthesized via degradation of siliceous FAU zeolite and recrystallization of degraded silicate species. As far as we know, the crystal of Sn-Beta in this work was minimum in size among all present directly hydrothermal synthesized ones. More importantly, the Sn contents in Sn-Beta could achieve to 2.39 wt % (Si/Sn = 81), breaking through the Sn content restriction of conventional fluoride-mediated method. In addition, the hydrophobicity of this resultant Sn-Beta zeolite was slightly inferior to Sn-Beta-F obtained via traditional fluoride-assisted route. Whereas the smaller crystal size of this Sn-Beta gave rise to relatively good diffusion performance for organics, which made it reveal high activities in the Baeyer-Villiger oxidant of ketones in particular employing bulky tert -butyl hydroperoxide as the oxidant. The current strategy provides an alternative and environmentally-friendly method for the hydrothermal synthesis of Sn-Beta without the assistance of fluoride and alkali metal ions, which can guide further development in metallosilicates crystal engineering in terms of greenization.
研究领域:
材料科学
·
催化
·
环境化学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2021
·Vol. 96
·期 8
·2238-2248
·
IF 3.174
Xiao-Yang Yue,Hui-Fang Ren,Chengming Wu,Jun Xu,Jifan Li,Chun-Ling Liu,Wen-Sheng Dong
BACKGROUND Methyl lactate is widely applied in the chemical, food, cosmetics and pharmaceutical industries. The conversion of carbohydrates over heterogeneous catalysts to methyl lactate is a promising environmentally benign process. RESULTS Hierarchical Sn-Beta zeolite (Sn-Beta) and corresponding bimetal-doped Beta zeolites (M-Sn-Beta; M = Zn, In, La, Ga, Ni) were prepared via a novel modified hydrothermal synthesis method to convert carbohydrates into methyl lactate. The introduction of Zn into Sn-Beta considerably improved the yield of methyl lactate from glucose, while for the catalysts containing In, La, Ga and Ni, such improvements were not observed. CONCLUSIONS A methyl lactate yield reaching up to 66.7% was obtained over Zn-Sn-Beta at 220 °C for 6 h. The enhanced catalytic performance was attributed to high Lewis acid density and strength, together with synergistic effects between framework Sn 4+ and Zn 2+ ions of Zn-Sn-Beta. Additionally, Zn-Sn-Beta demonstrated fructose and sucrose conversion into methyl lactate with yields of 68.4% and 70.0%, respectively. The Zn-Sn-Beta catalyst could be re-used at least five times with only a slight loss of methyl lactate yield. © 2021 Society of Chemical Industry (SCI).
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
危险品化学品经营许可证（带存储）