CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2021
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IF 3.171
Xiao Zhao,Xuan Shi,Zhongshun Chen,Long Xu,Chengyi Dai,Yazhou Zhang,Xinwen Guo,Dongyuan Yang,Xiaoxun Ma
A series of ZnO-ZrO 2 solid solutions with different Zn contents were synthesized by the urea co-precipitation method, which were coupled with H-ZSM-5 zeolite to form bifunctional catalysts. As a new benzene alkylation reagent, syngas was used instead of methanol to realize the efficient conversion of syngas and benzene into toluene and xylene. A suitable ratio of ZnO-ZrO 2 led to the significant improvement in the catalytic performance, and a suitable amount of acid helped to increase the selectivity of toluene/xylene and reduce the selectivity of the by-products ethylbenzene and C 9 + aromatics. The highest benzene conversion of 89.2% and toluene/xylene selectivity of 88.7% were achieved over 10% ZnO-ZrO 2 &H-ZSM-5 (Si/Al = 23) at a pressure of 3 MPa and a temperature of 450 °C. In addition, the effect of the zeolite framework structure on product distribution was examined. Similar to the molecular dynamics of aromatic hydrocarbons , H-ZSM-5 zeolites comprise 10-membered-ring pores, which are beneficial to the activation of benzene; hence, the conversion of benzene is higher. H-ZSM-35 and H-MOR zeolites exhibited small eight-membered-ring channels, which were not conducive to the passage of benzene; hence, the by-product ethylbenzene exhibits a higher selectivity. The distance between the active centers of the bifunctional catalysts was the main factor affecting the catalytic performance, and the powder mixing method was more conducive to the conversion of syngas and benzene.
研究领域:
催化化学
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材料科学
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DOI
高影响因子
CARBOHYDRATE POLYMERS
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2014
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IF 3.916
Yuxia Lv,Yaliang Chen,Ziqiang Shao,Renxu Zhang,Libin Zhao
Homogeneous tritylation of cellulose in 1-allyl-3-methylimidazolium chloride (AmimCl) ionic liquid with triphenylmethy chloride as regents, pyridine or 1-butylimidazole (BIM) as base was investigated, and subsequent acetylation of the 6- O -functionalized products was further studied. The structure of products was analyzed by FTIR and 13 C NMR spectroscopy and base influences on the structure were discussed as well. The solution with pyridine as base underwent heterogeneous–homogeneous–heterogeneous process and the obtained trityl cellulose (TC) had organized structure with trityl group located completely at C-6 position of cellulose with maximum DS trityl of nearly 1. In the case of BIM as base, the solution was homogeneous for the whole reaction, but the highest DS trityl was about 0.22, with trityl group located not only at position 6 but also partially at position 2. Subsequent acetylation of the TC led to products with a preferred functionalization of the unprotected secondary OH-groups.
研究领域:
化学
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材料科学
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产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2021
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IF 7.46
Shendan Zhang,Yunan Wang,Fengdong Qu,Tiju Thomas,Minghui Yang
Indium oxide (In 2 O 3 ) nanocubes modified by ruthenium oxide (RuO 2 ) on the surface are successfully prepared through hydrothermal method , calcination and impregnation in turn. The sensing properties of RuO 2 -modified In 2 O 3 sensing material are significantly enhanced even with low loading amount. The response values of RuO 2 -modified In 2 O 3 sensing material to TXM vapor containing benzyl group (including toluene, xylene and mesitylene) increase rapidly when compared to various volatile organic compounds (VOCs). Therein the RuO 2 -modified In 2 O 3 sensor displays a 36-times increase in response value to mesitylene (100 ppm) in contrast to un-modified one at 255 °C. The optimum operating temperature (OOT) decreases obviously from 375 °C of pristine In 2 O 3 one. The gas sensing enhancement mechanism can be explained by electronic and chemical sensitization. However, the reason for selectivity change will be (temporarily) investigated further later.
研究领域:
材料科学
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化学传感器
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DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
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2022
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IF 5.723
Yitao Zhao,Junjun Cheng,Peng Zhang,Xinhui Liu,Jianguo Zhuang,Yijun Yu,Qichao Zhao,Yuchen Wang,Xuedong Zhu,Fan Yang
Alkylation of benzene with carbon dioxide (CO 2 ) is significant for converting greenhouse gas and surplus benzene into value-added toluene and xylene. Herein, a bifunctional catalyst comprising Zn/Ga oxides and HZSM-5 zeolite was developed to efficiently promote the methylation of benzene with CO 2 and H 2 . This catalytic system exhibited excellent performance at 425 ℃ and 3.0 MPa, through which benzene conversion of 39.1% and total xylene/toluene selectivity of 92.7% have been achieved. Furthermore, the catalysts are carefully characterized; compositions of Zn/Ga oxides and Si/Al ratios of HZSM-5 zeolite are recognized as decisive factors for reaction activity and selectivity respectively. Additionally, primary reaction pathways are explored and testified to provide detailed understanding for the establishment of reaction networks, especially for mechanisms of ethylbenzene evolution. These findings are able to provide more deep insights into the process of benzene alkylation, which further facilitates the emergence of effective catalysts with potential industrial applications.
研究领域:
催化化学
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环境科学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
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2025
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IF 17.7
Jie Tuo,Zhenteng Sheng,Xianchen Gong,Qi Yang,Peng Wu,Hao Xu
Selective synthesis of value-added xylenes and para -xylene (PX) by CO 2 hydrogenation reduces the dependence on fossil resource and relieves the environment burden derived from the greenhouse gas CO 2 . Herein, modified MCM-22 zeolite combined with ZnCeZrO x solid solution is reported to catalyze the tandem CO 2 hydrogenation and toluene methylation reaction at a relatively low temperature (< 603 K), showing xylene selectivity of 92.4% and PX selectivity of 62% (PX/X, 67%) in total aromatics at a CO 2 conversion of 7.7%, toluene conversion of 23.6% and low CO selectivity of 11.6%, as well as giving high STY of xylene (302.0 mg·h –1 ·g cat –1 ) and PX (201.6 mg·h –1 ·g cat –1 ). The outstanding catalytic performances are closely related to decreased pore sizes and eliminated external surface acid sites in modified MCM-22, which promoted zeolite shape-selectivity and suppressed secondary reactions.
研究领域:
化学工程
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催化化学
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环境科学
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产品关联
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
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2013
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IF 4.612
Juxiang Ruan,Xiongjun Zuo,Qiwei Lang,Zhijian Zeng,Chao Li
This paper reports the preparation of a novel, silica-based, strong anion-exchange stationary phase from a 1,4-diazacyclohexane derivative. To prepare the difunctional strong anion-exchange stationary phase, activated silica beads were first bonded with 3-chloropropyltriethoxysilane and then reacted with 1-methylpiperazine followed by benzyl chloride . The silica beads, the strong anion-exchange stationary phase and its precusors were instrumentally characterized. Aromatic acids were separated with non-aqueous anion-exchange chromatography. After elution with eluant prepared in mixed solvents of water and methanol, the resulting 1,4-diazacyclohexane-derived, difunctional, strong anion-exchange stationary phase exhibited good separation and selectivity for the aromatic acids investigated. The effects of eluant pH, eluant ion concentration and solvent composites on the separations were investigated. Organic acids with different substituents were eluted in order of decreasing dissociation coefficients, with no observable peak shape differences.
研究领域:
分析化学
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色谱技术
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
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2025
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IF 9.8
Yaqiong Qin,Kunling Liu,Cong Nie,Fuwei Xie,Xiaoyu Wang,Ashraf Ali,Bing Wang,Qunye Hong,Wenjie Zhao
The increasing popularity of packaged beverages has raised concerns about the health risks associated with phthalate esters (PAEs), which are commonly found in plastics used for packaging. This study presents an eco-friendly approach for synthesizing a magnetic benzylated cyclodextrin-based hyper-cross-linked polymer (Fe 3 O 4 /BnCD-HCPP), in which FeCl 3 serves both as a catalyst for the Friedel–Crafts reaction and as an iron source for Fe 3 O 4 nanoparticles. The Fe 3 O 4 /BnCD-HCPP composite was used as an adsorbent to extract of PAEs from tea beverages via magnetic solid-phase extraction, followed by gas chromatography–mass spectrometry analysis. The optimized method exhibited excellent sensitivity, with limits of detection ranging from 0.1 to 0.5 μg L −1 . Additionally, the method achieved high recovery rates, ranging from 81.5 % to 118.5 %, and demonstrated precision (relative standard deviations <11.6 %) for PAEs spiked into tea beverages. Mechanistic studies indicated that the high extraction efficiency of Fe 3 O 4 /BnCD-HCPP for PAEs is due to its favorable pore size distribution, large specific surface area, and multiple interactions, including π-π stacking, hydrophobic force, and host-guest inclusion. This research not only provides an effective method for determining PAEs in complex aqueous matrices but also introduces a novel and sustainable approach for the fabrication of magnetic composites.
研究领域:
环境科学
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材料科学
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分析化学
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产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2025
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IF 3.9
Li Wang,Liyuan Li,Penggang Lv,Xin Gao,Yang Gao,Lu Han,Xuedong Zhu,Kake Zhu
A hierarchically structured ZSM-11/ZSM-5 intergrowth zeolite was generated using a polycationic organic structure-directing agent (OSDA), [-N+(CH2CH2CH2CH3)2-(CH2)8-]n[OH–]n, which is conceptually equivalent to bond-linked tetrabutylammonium (TBA), the frequently used OSDA for ZSM-11 synthesis. The produced ellipsoidal crystals have a major axis length of 130–240 nm and a minor axis length of 75–120 nm, made up of aligned nanocrystals of 44 to 83 nm, to construct an auxiliary macro- to mesopore network ranging from 45 to 80 nm. The Si/Al ratio can be manipulated from 50 to ∞, and the intergrowth exhibits acidity comparable to that of ZSM-5, which is distinct from previous reports that formation of hierarchical porosity or intergrowth often compromises the inherent acidity of zeolitic crystals. Such hierarchical architecture also endows the material with enhanced transport properties, as validated by 2-methylhexane adsorption measurements. In the catalytic methylation of meta-xylene with methanol, the hierarchical ZSM-11/ZSM-5 zeolite exhibited superior performance to that of ZSM-5, with enhanced activity and total trimethylbenzene and tetramethylbenzene selectivity, which was elevated from 28% to 39%. These catalytic merits stem from the combined effects of preserved acid strength, optimized pore connectivity, and alleviated diffusion limitations.
✓ 已验证
DOI
高影响因子
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