CATALYSIS COMMUNICATIONS
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2020
·
IF 3.612
Shanqing Yu,Jiasong Yan,Wei Lin,Jiexiao Zhang,Jun Long
Zirconium-modified Y zeolites (ZrUSY) were prepared by impregnation of the zeolite with anhydrous-ethanol and aqueous ion exchange methods. The ZrUSY samples were characterized by powder X-ray diffraction, nitrogen physisorption, and Fourier transform infrared spectroscopy. The results indicated that ZrUSY prepared by the impregnation with anhydrous-ethanol method showed higher crystallinity, specific surface area and hydrothermal stability. The incorporation of Zr into other Y zeolites leads to an increase of the Brønsted acid site concentration and a decrease of the Lewis acid site concentration compared to the ultra-stable Y zeolite (USY). The ZrUSY was much more favorable towards heavy oil FCC conversion with decreasing coke yield and improving olefins selectivity.
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
MICROPOROUS AND MESOPOROUS MATERIALS
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2022
·
IF 5.876
Bo Meng,Shenyong Ren,Xinyue Zhang,Kang Chen,Wenkai Wei,Qiaoxia Guo,Baojian Shen
Brønsted acid of zeolite Y plays an important role in catalytic cracking reaction. However the proportion of strong Brønsted acid in conventional zeolite Y is small which limits the efficiency of transformation. This work described a way to achieve the goal of significant increasing the density of strong Brønsted acid via introducing Zr 4+ into the framework of zeolite Y. The density of strong Brønsted acidity increased from 0.085 (HY) to 0.208 mmol/g ([Zr,Al]-HY). Systematic characterization results showed that the introduction of Zr 4+ could produce more Si(1Al) but less Si(3Al) and Si(2Al) species in zeolite which was responsible for the high density of Brønsted acid. And abundant mesopores were also formed during the Zr 4+ implanting. For the catalytic cracking results of n-octane, the conversion on [Zr,Al]-HY was 1.67 times of that on conventional HY. The apparent activation energy of cracking n-octane on [Zr,Al]-HY was reduced to 73.3%, which indicated that the increase of strong Brønsted acid had significant effect on catalytic cracking. On the other hand, a large number of mesoporous structures of [Zr,Al]-HY provided a good foundation for the catalytic cracking of steric hindered 1.3.5-triisopropylbenzene (1,3,5-TIPB).
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 Inorganic and Organometallic Polymers and Materials
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2022
·Vol. 32
·期 9
·3496-3507
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IF 3.518
Yang Nana,Gou Lizheng,Bai Zhitao,Cheng Fangqin,Guo Min,Zhang Mei
Zeolite Y was successfully synthesized by a hydrothermal method using bauxite tailings as starting materials to effectively remove Pb(II) from wastewater. It was shown that pure zeolite Y with typical octahedral microstructure was obtained when n(SiO 2 /Al 2 O 3 ) was 7, n(H 2 O/Na 2 O) was 35, hydrothermal at 100 °C for 10 h. The results of N 2 adsorption–desorption showed that the prepared samples possessed relatively high BET surface areas of 875 m 2 /g. The adsorption capacity of Pb(II) by the zeolite Y in aqueous solutions reached 443.87 mg/g, and the maximum removal efficiency was 99.95%. In addition, after five circulating adsorptions, the removal efficiency of Pb(II) was maintained as high as 99.2%, indicating that zeolite Y had excellent reusability. The selective adsorption results of Pb 2+ –K + –Cd 2+ ternary system solution revealed that when the concentration ratio was 1:1:1, the removal efficiency of Pb(II) was 5.5 times of Cd(II), and K(I) was almost not adsorbed. The high adsorption capacity and excellent selective adsorption of Pb(II) indicated that the zeolite Y could be a suitable absorbent for lead removal, moreover, this work explored a new way to improve the utilization of bauxite tailings.
研究领域:
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
RSC Advances
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2021
·Vol. 11
·期 5
·2866-2871
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IF 3.361
Hui Cheng,Yanfeng Yin,Jianbo Tang,Donghua Fan,Jan J. Huang,Shengye Jin
All-inorganic perovskite materials have emerged as highly promising materials for solar cells and photoelectronic applications. However, the poor stability of perovskites in ambient conditions significantly hampers their practical applications. In this work, we report a three-step synthesis of size tunable CsPbX3 (X = Br, Cl, or I) quantum dots (QDs) embedded in zeolite-Y (CsPbX3-Y), which involves efficient chemical transformation of non-luminescent Cs4PbX6 to highly luminescent CsPbX3 by stripping CsX through an interfacial reaction with water. We show that the size and the emission of CsPbX3 in CsPbX3-Y can be tuned by the amount of water added as well as the halide composition. More importantly, the as-prepared CsPbX3-Y show significantly enhanced stability against moisture upon protection by zeolite-Y. This work not only reports a new pathway for the preparation of highly luminescent CsPbX3 but also provided new insights into the chemical transformation behavior and stabilization mechanism of these emerging perovskites.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Yufan Zhang,Pu Ma,Heyun Fu,Xiaolei Qu,Shourong Zheng
Chloroanisoles is a class of odorous pollutants commonly identified in drinking water . In the present study, we confined noble metal palladium (Pd) in the micropores of zeolite Y ( ie -Pd@Y) using an ion exchange method, and applied it for the catalytic hydrodechlorination removal of chloroanisoles (represented by 2,4,6-trichloroanisole/TCA) in water. Pd supported on zeolite Y surface ( im -Pd/Y, prepared by conventional impregnation method) was used as the benchmarking catalyst. The characterization results revealed that ie -Pd@Y had smaller Pd particle size and higher Pd n+ /Pd 0 ratio than im -Pd/Y. The catalytic hydrodechlorination of TCA followed a concerted dechlorination pathway and the Langmuir-Hinshelwood model. The ie -Pd@Y catalysts with different Pd loadings exhibit excellent catalytic activities with more than 95% of TCA removed within 30 min, which is far superior to the im -Pd/Y catalysts (27–70%). Moreover, due to the confinement effect of zeolite Y, ie -Pd@Y displayed enhanced catalytic stability as compared with im -Pd/Y. The initial activity of ie -Pd@Y was more than 20 times higher than that of im -Pd/Y after five reaction cycles. Additionally, with the assistance of sieving effect, ie -Pd@Y displayed much stronger capability against the interference from dissolved organic matter than im -Pd/Y. The present results demonstrate that the confined catalysts ie -Pd@Y can be applied in liquid phase catalytic hydrogenation to effectively eliminate halogenated odorants in waters.
研究领域:
环境科学
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催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2016
·Vol. 33
·期 6
·1931-1937
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IF 1.408
Fu Xiaoqin,Sheng Xiaoli,Zhou Yuming,Fu Zhiwei,Zhao Shuo,Zhang Zewu,Zhang Yiwei
Well-dispersed hierarchical zeolite Y, structure-directed by ionic liquid 1-methyl-3-[3'-(trimethoxysilyl) propyl] imidazolium chloride, was synthesized for the first time using a novel ultrasonic/microwave synergistic synthesis (UMSS). The time required for the synthesis of zeolite Y by UMSS method was remarkably reduced to 6 h instead of 24 h under conventional hydrothermal conditions. The structures of all samples were characterized by XRD, BET, FT-IR, SEM and TEM. The results clearly demonstrated that the UMSS is a promising strategy to achieve zeolite Y with improved crystallinity, large BET surface area, bulky mesopore volume, well-dispersed morphology, small zeolite nanoparticle. The catalytic activity of hierarchically micro-mesoporous zeolite Y was evaluated by using the alkylation of o-xylene with styrene. Mesoporous zeolite Y synthesized by UMSS method showed significantly higher catalytic activity, stability and reusability, compared with conventional hydrothermal synthesis. It might be ascribed to its large mesoporous volume, small crystal nanoparticle and high surface area, minimizing the diffusion length as the reactant molecules diffuse into the pores, and correspondingly the products diffuse out of zeolites. This study suggests that UMSS method is a good alternative for the synthesis of micro-mesoporous zeolite Y, which may be of remarkable benefit for industrial applications.
研究领域:
材料化学
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催化化学
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纳米材料科学
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工业化学
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多孔材料
✓ 已验证
DOI
高影响因子
CELLULOSE
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2020
·Vol. 27
·期 15
·8827-8841
·
IF 4.21
Al-Ghamdi Youssef O.,Khan Shahid Ali
Abstract Performance of polymer-based Au catalysis depends on the size of Au particles and the structure of polymer host materials. In the current studies, the carboxymethyl cellulose-chitosan (CMC-CH) sheet was synthesized by layering CMC on CH sheet, while CMC-CH-CBV 780 zeolite Y (CMC-CHZY) sheet was synthesized by coating the CMC layer on a sheet of CH-incorporated CBV 780 zeolite Y (ZY). The CMC-CH or CMC-CHZY sheets were individually immersed in Au(III) salt solution, which was converted to Au 0 NPs by treating with NaBH 4 to synthesize Au/CMC-CH or Au/CMC-CHZY catalysts respectively. Both the synthesized Au catalyst activities were compared against the discoloration of methylene blue (MB) and Congo red (CR) dyes as well as the reduction of 4-nitrophenol (4-NP). It was revealed that Au/CMC-CHZY catalyst showed excellent catalytic performance against all the pollutants. Furthermore, the apparent rate constant k app (3.3 \(\times\) 10 − 1 min −1 ), of Au/CMC-CHZY catalyst was found higher against MB dye discoloration as compared to CR and 4-NP. It was also observed that MB discoloration followed pseudo-first-order while CR and 4-NP followed the zeroth-order kinetics. The catalyst alters the mechanism of a chemical reaction and so does the order of the reaction, therefore, observed different orders of reaction in the current study. Graphic abstract
研究领域:
材料科学
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环境科学
·
化学工程
✓ 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）