Frontiers of Environmental Science & Engineering
·
2023
·Vol. 17
·期 8
·1-10
·
IF 6.4
Zhang Zhou,Huo Kai,Yan Tingxuan,Liu Xuwen,Hu Maocong,Yao Zhenhua,Liu Xuguang,Ye Tao
Photocatalytic degradation is a promising way to eliminate dye contaminants. In this work, a series of TiO 2 /ZSM-11 (TZ) nanocomposites were prepared using a facile solid state dispersion method. Methyl orange (MO), methylene blue (MB), and rhodamine B (RhB) were intentionally chosen as target substrates in the photocatalytic degradation reactions. Compared to pristine TiO 2 , negative effect was observed on MO degradation while promoted kinetics were collected on MB and RhB over TZ composites. Moreover, a much higher photocatalytic rate was interestingly achieved on RhB than MB, which indicated that a new factor has to be included other than the widely accepted electrostatic interaction mechanism to fully understand the selective photodegradation reactions. Systematic characterizations showed that TiO 2 and ZSM-11 physically mixed and maintained both the whole framework and local structure without chemical interaction. The different trends observed in surface area and the photo-absorption ability of TZ composites with reaction performance further excluded both as the promotion mechanism. Instead, adsorption energies predicted by molecular dynamics simulations suggested that differences in the adsorption strength played a critical role. This work provided a deep mechanistic understanding of the selective photocatalytic degradation of dyes reactions, which helps to rationally design highly efficient photocatalysts.
研究领域:
环境科学
·
材料科学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Xiangyou Kong,Pengfei Nie,Ling Shi,Maocong Hu,Pingping Zhang,Xia Li,Zhiyi Wang,Xuguang Liu
Fast synthesis of zeolite with hydrothermal method is a challengeable topic. In this work, we reduced the crystallization time to ~1/3 of conventional method by adding a small amount of graphene oxide (GO) into ZSM-11 synthesis gel. The embedment of GO into ZSM-11 crystal was confirmed by XPS, TG, and Raman spectra, while it modified morphology, porosities, component, and surface acidity of ZSM-11 as characterized by SEM, TEM, XRF, N 2 -physisorbtion, NH 3 -TPD, and Py-IR. The non-classical nucleation, which governed the required crystallization time, was further proposed and evidenced by both experimental observations and molecular dynamic modeling. It clearly illustrated the positive role of GO on promoting the formation of meta-stable phase during non-classic nucleation, resulting into much shorter crystallization time. GO embedded ZSM-11 demonstrated high activity (reaction rate and TOF), improved selectivity, and superior stability for benzene alkylation with ethanol, which can be attributed to the regulated surface acidity and diffusion properties. This work opens up a new perspective to synthesize ZSM-11 zeolite with superior catalytic performance in a highly efficient and environmental manner.
研究领域:
材料科学
·
催化化学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Meng Li,En-Hui Yuan,Weijiong Dai,Yan Wang,Anning Zhou,Zhong-Wen Liu
Rapid and precise crystallization of zeolites with targeted topologies remains a significant challenge. Herein, we report a facile strategy for synthesizing ZSM-11 within 12 h by introducing cationic poly(dimethyl diallyl ammonium chloride) (PDDA) into the precursor gels. This approach achieves an 80-fold acceleration versus conventional methods while yielding nanosized crystals with hierarchical pore architectures. We demonstrate that unique confined nano-interfaces/nano-microenvironment formed via electrostatic assembly of cationic PDDA and negatively charged silica precursors facilitate enrichment of crystallization nutrients, e.g. tetrabutylammonium hydroxide, water, and silica/alumina species. This unique confined nano-interfaces/nano-microenvironment promotes in-situ depolymerization-condensation reactions of the silica/aluminum species and shortens nutrient transport pathways, collectively accelerating nucleation and crystallization. The mechanism is further supported by the comparative experiments via changing synthesis parameters including PDDA(C 8 H 16 NCl)/SiO 2 ratio, polymerization degree of PDDA, and addition of silicalite-2 seeds. The rapidly synthesized ZSM-11 exhibits superior methanol-to-olefins (MTO) performance, demonstrating tremendously extended catalyst lifetime and high coke resistance relative to conventionally prepared counterparts. This work advances a generalizable route to efficient synthesis of zeolite catalysts.
研究领域:
材料化学
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催化化学
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纳米材料
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多孔材料
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化学工程
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工业催化
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功能材料
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2022
·
IF 5.876
Xiangyou Kong,Jinyang Zhao,Kai Huo,Ling Shi,Zhenhua Yao,Jianan Yang,Maocong Hu,Xia Li,Xuguang Liu
Alkali metal cations showed significant effects on the zeolite synthesis process as well as its structure while the mechanism is still under debate. In this work, ZSM-11 zeolites were synthesized with the addition of four alkali metal cations (Li + , Na + , K + , Cs + ). Except for different morphology and pore structure observed in the four samples, ZSM-11 synthesized with the presence of Li + demonstrated low synthesis efficiency and weak acidic properties compared to those with the addition of Na + , K + , and Cs + ions. Both DFT calculations and MD simulations were further performed to investigate the precursor reactions between silicates and aluminates as well as the polycondensation of two silicon-aluminum tetrahedral structural units. Except for the widely used factors including polarizable ability parameter ( g i ) and structural parameter ( 0 W ), two new parameters, i.e., polarizability ( α 0 ) and first hyperpolarizability ( β 0 ), were first employed as the descriptor to unravel the effects of alkali metal ion on ZSM-11 zeolite synthesis and properties. Obtained ZSM-11 samples exhibited the distinct catalytic performance for benzene alkylation with ethanol, which was attributed to the different structure and acidity properties. This work provides new insights into the deep understanding of the effects of alkali metal cations on zeolite synthesis in a closely mechanistic view.
研究领域:
材料科学
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催化化学
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计算化学
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产品关联
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 39
·24015-24021
·
IF 3.108
Zhenhao Wei,Kake Zhu,Lanyu Xing,Fan Yang,Yunsheng Li,Yarong Xu,Xuedong Zhu
Transforming natural kaolin into pure-phase hierarchical aggregates of nano ZSM-11 has been achieved by using a novel tetrabutylphosphonium hydroxide as a structure-directing agent via steam-assisted crystallization. The hierarchical ZSM-11 possesses a small particle size (about 240 nm), large surface area (428 m2 g−1), and abundant mesopores (0.30 cm3 g−1). Moreover, the hierarchical ZSM-11 exhibits prolonged catalytic lifetime and promoted aromatic selectivity in the methanol-to-aromatics reaction. The superior catalyst stability is attributed to the better capacity of accommodating the coke and a lowered coking rate.
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
ACS Applied Nano Materials
·
2021
·
IF 5.097
Zhongwen Dong,Chuanyu Yang,Dongpu Zhao,Yanan Wang,Weifeng Chu,Zhaochi Feng,Xiangxue Zhu,Wenjie Xin,Yongchen Shang,Shenglin Liu,Longya Xu
The interzeolite transformation approach has been used extensively for the quick synthesis of zeolites at a lower cost. Herein, an interzeolite transformation method for the quick synthesis of co-crystalline ZSM-5/ZSM-11 (CDM-5) nanoaggregates has been developed by precisely controlling the synthesis parameters and using 1,6-hexamethylenediamine as an organic structure-directing agent. In contrast, the irregular CDM-5 zeolite block obtained from an amorphous aluminosilicate gel takes a longer crystallization time using the conventional method. Combined with the related results of characterization, UV-Raman spectra show that double 6-membered rings in the parent USY zeolite framework are broken, and an ordered aluminosilicate aggregate species (OAAS) containing 4-membered rings (4Rs) are formed during the interzeolite transformation. HRTEM and SEM images demonstrate that the block OAAS is dissolved into amorphous nanoparticles, followed by converting into CDM-5 nanoaggregates. These results reveal that an OAAS is essential for the synthesis of CDM-5 nanoaggregates via the interzeolite transformation method. In addition, the CDM-5 nanoaggregate catalyst exhibits superior stability and resistance to carbon deposition in the alkylation reaction of benzene with ethanol compared with the irregular block CDM-5 catalyst.
研究领域:
化学工程
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材料科学
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催化
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纳米技术
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2025
·
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
RSC Advances
·
2015
·Vol. 5
·期 39
·31195-31204
·
IF 3.84
Wen Song,Zhiting Liu,Liping Liu,Anne Ladegaard Skov,Nan Song,Guang Xiong,Kake Zhu,Xinggui Zhou
A route to generate hierarchically porous zeolite ZSM-11 has been paved via solvent evaporation induced self-assembly assisted by hexadecyltrimethoxysilane to produce a preformed dry gel, followed by its subsequent transformation into zeolite via steam-assisted-crystallization. The crystallization in dry gel has been found to undergo an orientated attachment growth mechanism whereby hexadecyltrimethoxysilane directs the formation of auxiliary mesopores and inhibits the fusion of primary nucleates. Measurements such as XRD, SEM, TEM, N2-physisorption, and TEM for an inverse replica of Pt derived from hierarchical ZSM-11 have been conducted to characterize the textural properties of the material. Ammonia temperature-programmed-desorption (NH3-TPD) measurements and infrared spectra using probe molecules such as pyridine (Py-IR) and 2,4,6-collidine (Coll-IR) have been collected to investigate the acidic properties as well as the accessibility of the acid sites. The hierarchical ZSM-11 possesses more acid sites on the mesopore surfaces that are accessible towards large probe molecules such as 2,4,6-collidine. This improvement together with the enhanced pore-connectivity brings about an increase in 1,3,5-triisopropylbenzene cracking activity and benzene selectivity with respect to a conventional counterpart.
研究领域:
材料科学
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化学工程
·
催化
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Ye Li,Yong Wang,Honghao Bai,Shishuai Li,Xiaomin Li,Xiaoqing Wang,Libo Li,Jinping Li,Jiangfeng Yang
The economically efficient separation of ethane (C 2 H 6 )/ethylene (C 2 H 4 ) presents challenges in the petrochemical industry, and the use of traditional adsorbents zeolite provides a reliable guarantee for maintaining the economic viability of adsorption separation technology. In this study, we investigate the impact of different silica-alumina ratios (SiO 2 /Al 2 O 3 = 40, 500, and 1500) of high silica zeolites ZSM-11 on the C 2 H 6 /C 2 H 4 separation performance to develop efficient C 2 H 6 selective adsorbents. The results show that the C 2 H 6 adsorption capacity and C 2 H 6 /C 2 H 4 selectivity of ZSM-11 increase as the silica-alumina ratios increases. The pure silica zeolite (ZSM-11(1500)) exhibits the highest adsorption capacity for C 2 H 6 (59.19 cm 3 /g) and the highest selectivity for C 2 H 6 /C 2 H 4 (2.04), which were superior to ultra-high silica sample (ZSM-11(500)) (55.06 cm 3 /g and 1.62, respectively) and high silica sample (ZSM-11(40)) (47.28 cm 3 /g and 1.23, respectively), at 273 K and 1 bar. The mixed gas breakthrough experiments results show that pure silica sample has outstanding C 2 H 6 /C 2 H 4 separation ability. The PSA simulation calculated data demonstrating promising potential for industrial applications. Importantly, this separation performance remains unaffected even in the presence of H 2 O.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Qingjun Yu,Wenjing Wu,Jinghui Wei,Jie Zhang,Shunzheng Zhao,Xiaolong Tang,Honghong Yi
Catalytic combustion is one of the most effective technologies applied to volatile organic compounds (VOCs) emission control, in which zeolites have been regarded as a unique support or even a catalyst due to their unique shape & size features as well as the interaction between the zeolitic structural groups and the extraneous metal species. Particularly, Mn-based zeolites have attracted great attention as a promising catalyst for their superior redox ability on account of mixed valent properties. In this work, a series of Mn-contained samples with different compositions were synthesized to investigate the role of Al and Mn in zeolite for catalytically combusting VOCs. As redox active sites, Mn is well dispersed in the form of oligomeric Mn oxide clusters on the surface to optimize catalysis. With Al and Mn introduced into zeolite simultaneously, more defects for the activation of adsorbed oxygen appeared on superficial MnO x , but Al prevented Mn being incorporated in ZSM-11(MEL) distinctly, which is a principal factor affecting the catalytic activity . Additionally, Pt was introduced to further enhance the catalytic performance, whose function in Mn-MEL was also clarified in detail via XPS and other characterization techniques. Results demonstrated that appropriate Mn/Pt ratio could create suitable surface morphology (the interface of Pt-MnO x ) for the adsorption of oxygen species via the synergistic catalytic effect caused by Pt and Mn.
研究领域:
环境科学
·
催化化学
✓ 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）