CATALYSIS TODAY
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2021
·
IF 6.766
Lijie Pei,Jianxin Cao,Fei Liu,Anjie Yang,Mengqin Yao,Tianxiang Zhao,Xiaodan Wang,Sibudjing Kawi
The catalytic properties of bifunctional ZSM-5@t-ZrO 2 catalyst for methanol thiolation were revealed by using methanol and H 2 S as probe molecules. Taking the ZSM-5/t-ZrO 2 physically-blended catalyst, pure ZSM-5 and t-ZrO 2 as control catalysts, we investigated the characteristics of adsorption and transformation of different reaction molecules on or over different catalysts by combination of in-situ diffuse reflectance Fourier transform infrared spectroscopy (Drifts) and a variety of techniques including XRD, XPS, XRF, FT-IR, N 2 adsorption-desorption, CO 2 /NH 3 -TPD, and DSC. The results showed that the synergistic effect of acid sites between ZSM-5 phase and t-ZrO 2 phase in the bifunctional catalyst enhanced the adsorption and dissociation of methanol molecules, while the base sites in t-ZrO 2 phase were mainly responsible for the adsorption and dissociation of H 2 S molecules. Due to the small specific surface area of pure t-ZrO 2 catalyst, precursor species for sulfur deposition and carbon deposition were easily formed. Presulfurization could improve the initial activity of methanol thiolation and shorten the induction period. The dissociation of H 2 S at the base sites was the rate-determining step of the bimolecular reaction, and the appropriate increase of base sites in the bifunctional components could construct the matching formation rate of sulfhydryl and methoxy groups. At the same time, the special composite structure and meso-microporous system of ZSM-5@t-ZrO 2 could effectively reduce the formation rate of carbon and sulfur deposits.
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
MATERIALS CHEMISTRY AND PHYSICS
·
2016
·
IF 2.101
Shunyu Han,Zheng Wang,Longyue Meng,Nanzhe Jiang
Mesoporous ZSM-5 zeolites were synthesized by using hydrophilic carbon black as a hard template. Hydrophobic carbon black was oxidized with sodium hypochlorite solution then dispersed into the synthetic precursor, and hydrothermally treated by omitting the evaporation process. The samples were characterized by SEM, TEM, XRD , nitrogen adsorption/desorption and NH 3 -TPD measurements. As a result, mesoporous ZSM-5 zeolites were obtained in the morphology of single crystal like aggregates (about ∼2 μm) with intra-mesopores in the range of 5–18 nm. Textural properties and acidity of mesoporous ZSM-5 zeolites were varied by adjusting the amount of carbon black used. In the toluene disproportionation, mesoporous ZSM-5 templated by hydrophilic carbon black showed more active in toluene conversion and more selective to the para -xylene than conventional zeolite, and even comparable to the commercial zeolite catalyst.
研究领域:
材料科学
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催化化学
✓ 已验证
DOI
高影响因子
BioEnergy Research
·
2013
·Vol. 6
·期 4
·1173-1182
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IF 4.25
Shao Shanshan,Zhang Huiyan,Xiao Rui,Shen Dekui,Zheng Jian
The conversion of three major biomass derivates was conducted in a quartz tubular fixed bed reactor over a ZSM-5 catalyst. As the model compounds of polyols, saturated furans and unsaturated furans, ethylene glycol (EG), tetrahydrofuran (THF) and furan were pyrolyzed to find out the influence of chemical structure on the catalytic characteristics. The effect of pyrolysis temperature (400 ∼ 650 °C), weight hourly space velocity (2.9 ∼ 15.5 h −1 ) and partial pressure (2.12 ∼ 20.49 Torr) on the feed conversion, product yield and selectivity were investigated. The hydrogen to carbon effective ratio (H/C eff ) was referred to, to analyze the capacity of biomass derivates being converted to chemicals (olefins and aromatics). The results showed that the existence of rings and C=C had great effect on the catalytic characteristics. The conversion of furan was much lower (mainly less than 60 %) than that of EG and TH,F which were close to 100 %. It was also found that the chemical yield of THF was slightly more than that of EG, which can be attributed to its relative higher H/C eff of 1.5. Furan produced the highest coke yield, which was more than 15 %, whereas that of EG and THF was only around 5 %. The serious coking of furan led to the lowest chemical yield, which was less than 35 %. This study paves a way for the mechanism study on catalytic characteristics of biomass-derived feedstocks over zeolite catalysts.
研究领域:
能源科学
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催化化学
✓ 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
Hao Zhang,Guang-Ren Qian,Hong Liu
Alumina composites containing microporous ZSM-5 (Z-5) and mesoporous ZSM-5 (MZ-5), corresponding to x ZA and x MZA, were developed by incorporating Z-5 and MZ-5 into γ - Al 2 O 3 , respectively. The two series of NiMoS/ x MZA and NiMoS/ x ZA catalysts were prepared with these two composites as supports, respectively, and were used for the simultaneous hydrodesulfurization (HDS) of thiophene (T) and benzothiophene (BT). The results show that NiMoS/ x MZA series catalysts exhibit higher HDS activity than that of NiMoS/ x ZA and NiMoS/γ-Al 2 O 3 , and the HDS activity of NiMoS/ x MZA catalysts increases with the increase of MZ-5. The high HDS activity can be mainly attributed to the synergistic effects of the efficient diffusing pore channels, high dispersion of type II NiMoS phases, suitable acidity, and moderate Mo-support interaction. Moreover, the product distribution of HDS shows that the NiMoS/ x MZA catalysts possess the dominant direct desulfurization (DDS) selectivity and the selectivity increases with the increase of MZ-5 content due to more corner sites and suitable Brønsted (B) acid sites, whereas the NiMoS/ x ZA catalysts perform more excellent hydrogenation (HYD) selectivity, and the selectivity increases with the increase of Z-5 content because of the existence of more edge sites. Based on this, the possible reaction network for T and BT hydrodesulfurization over the catalysts are proposed.
研究领域:
催化化学
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能源化工
✓ 已验证
DOI
高影响因子
ACS Catalysis
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2016
·
IF 9.307
Shanhui Zhu,Yanfeng Xue,Jing Guo,Youliang Cen,Jianguo Wang,Weibin Fan
The high-yield synthesis of the biofuel γ-valerolactone (GVL) is a challenging task, which currently stems from the depolymerization of cellulose to levulinic acid, followed by its hydrogenation. We have developed a novel integrated process for the production of GVL from hemicellulose without using liquid acids and external hydrogen. The hemicellulose feed underwent hydrolysis and consecutive dehydration to produce furfural over ZSM-5 catalyst. Subsequently, the formed furfural with 2-propanol performed tandem conversion to GVL over Au/ZrO2 catalyst combined with ZSM-5. This process gave a high yield of GVL under mild conditions: up to 61.5% based on hemicellulose. The outstanding performance was mainly ascribed to the strong interface interaction of Au with ZrO2 species, large amounts of medium-strength acid sites over ZSM-5, and efficient synergy between active metal and acid sites.
研究领域:
生物化学
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催化化学
✓ 已验证
DOI
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2018
·Vol. 34
·期 4
·661-664
·
IF 1.248
Yi Ting,Li Jingwei,Zhang Yibo,Yang Xiangguang
Hollow-ZSM-5 was synthesized by a traditional hydrothermal method without alcohol, and a novel na-no-sized Ce-Cu/hollow ZSM-5 sample was prepared by conventional incipient wetness impreganation. The catalysts were characterized by TEM, SEM, XRD, NMR and N 2 adsorption-desorption. The results indicate that the hollow-ZSM-5 has a good MFI structure with large surface area. The synthesized CeO 2 -CuO/hollow ZSM-5 showed an excellent catalytic activity for NO x conversion(90% NO x conversion were obtained) in the temperature range of 340–550 °C under GHSV=480000 mL·g ‒1 ·h ‒1 due to its appropriate redox ability and acidity.
研究领域:
环境科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2022
·
IF 4.889
He Han,Anfeng Zhang,Limin Ren,Xiaowa Nie,Min Liu,Yi Liu,Chuan Shi,Hong Yang,Chunshan Song,Xinwen Guo
Shape-selective alkylation of toluene with methanol is one of the most attractive promising synthetic routes to para -xylene. To date, modified ZSM-5 zeolites are considered to be one of the best candidate catalysts for this reaction. Although the para -selectivity could be tuned to approaching 100% by modification of the zeolite and optimization of reaction conditions, at present, there is still a lack of effective means to inhibit the rapid deactivation of the catalysts due to coke formation. In this work, a coke-resistant (Pt + Ni)/ZSM-5 zeolite with excellent stability for shape-selective alkylation of toluene with methanol to para -xylene is developed. The pore structure and acid properties of the zeolite are effectively tuned to ensure high para -selectivity. Meanwhile, the co-existence of Pt and Ni species in this catalyst plays the critical role in inhibiting coke formation, as the two species concurrently impede the formation of olefins, the main coking precursors, via two distinctive mechanisms.
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
Fuwei Li,Xiaofeng Wang,Hengshuo Gu,Hongbing Fu,Asad Ali,Hongfei Lin,Zhixia Li
Minimizing the catalyst cost is critical to achieving long-term economic feasibility for obtaining bio-chemicals directly from biomass. In the present study, low cost ZSM-5 was synthesized via hydrothermal crystallization of the activated aluminosilicate gel without adding any organic ammonium templates and additional seed crystals . The activation process promoted the depolymerization of the silica-alumina species and the formation of active pasty gel containing nucleation precursors, consequently accelerating the subsequent crystallization reaction. The addition of eucalyptus sawdust (ES) in the synthesis process increased the BET (Brunauer-Emmett-Teller) surface area and acidity of the resultant zeolites . The ES-mediated ZSM-5 (AGZ-10) achieved a higher benzene, toluene, ethylbenzene and xylene (BTEX) carbon yield (18.9 %) from co-cracking of ES and waste plastics (WP) (ES/WP mass ratio at 1:1) at 500 °C and exhibited better synergistic effect and anti-coking ability compared to the commercial ZSM-5. The results provide an efficient synthetic strategy to produce low-cost zeolites, and a promising technique to effectively utilize biomass and plastic wastes.
研究领域:
能源与环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2025
·
IF 3.9
Long Zhang,Linjie Guan,Jiashu Liu,Song Song,Ye Tian,Xingang Li
Graphical N-ZSM-5–40 nanosheet zeolites prepared by seed-induced growth coupled with mineralization agent assisted method exhibited remarkable activity and stability in conversion of lactic acid to lactide. Enhanced diffusion and accessible Brønsted acid sites amount benefit the production of lactide. Lactide (LD) is the key building block of high-quality polylactic acid (PLA), a biodegradable polymer with broad industrial applications. Developing an efficient catalyst for one-step conversion of lactic acid to LD is critical for the PLA industry. Herein, N-ZSM-5–40 nanosheets with a thickness of about 20 nm were successfully synthesized and first applied to this esterification reaction. The yield of LD over N-ZSM-5–40 reaches 60.5% after reaction at an oil bath temperature of 140 °C for 5 h. Systematic characterization revealed that reducing the b-axis thickness of MFI-type nanosheet zeolites improves Brønsted acid sites (BASs) accessibility, which was identified as a critical factor governing the yield of LD. Time-dependent product distribution experiments demonstrate that the nanosheet structure of N-ZSM-5–40 facilitates faster cyclization of L 2 A to LD, compared to commercial C-ZSM-5–40. In-situ FTIR results reveal that N-ZSM-5–40 nanosheets have a strong ability to adsorb and activate carbonyl groups, which promotes the rapid conversion of lactic acid to LD. Given the aforementioned advantages, ZSM-5 nanosheets hold great potential for guiding the development of industrial catalysts for sustainable LD synthesis.
研究领域:
催化化学
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材料科学
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绿色化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2018
·Vol. 6
·期 42
·21178-21185
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IF 9.931
Hao Chen,Xu Shi,Jianfang Liu,Kecheng Jie,Zihao Zhang,Xiaobing Hu,Yimei Zhu,Xiuyang Lu,Jie Fu,He Huang,Sheng Dai
Zeolite materials play a significant role throughout the oil refining and petrochemical industry. Microporous ZSM-5 has a high degree of crystallinity but low mass transfer, while hierarchical ZSM-5 shows a low degree of crystallinity as well as acidity. In this work, we first report the synthesis of ZSM-5 with a new morphological structure, which has nanocrystalline ZSM-5 particles on the surface of an intact ZSM-5 zeolite. This not only improved the mass transfer in microporosity but also overcame disadvantages of hierarchical ZSM-5 including low degrees of crystallinity and acidity. This new and very efficient structure with both intracrystal microporosity and intercrystal macroporosity, formed by secondary crystallization after the intact ZSM-5 zeolite was synthesized, was verified by transmission electronic microscopy, N2 adsorption and desorption, and X-ray diffraction. The obtained ZSM-5 zeolite showed a uniform size (∼200 nm), high crystallinity acidity, and a suitable hierarchical structure that exhibited excellent properties in the catalytic fast pyrolysis of cellulose to produce aromatics.
研究领域:
化学工程
·
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
Separations
·
2024
·Vol. 11
·期 2
·39
·
IF 2.5
Zhenhua Sun,Qingxiang Shu,Qikun Zhang,Shaopeng Li,Ganyu Zhu,Chenye Wang,Jianbo Zhang,Huiquan Li,Zhaohui Huang
ZSM-5 zeolite is a kind of high-value-added porous aluminosilicate zeolite. The use of the coal gasification slag utilization process by-product desilication liquid as a silicon raw material to replace the current raw materials such as water glass will help reduce production costs and achieve high-value utilization of solid waste. ZSM-5 zeolites for volatile organic compounds (VOCs) adsorption were prepared by a one-step hydrothermal method using the desilication solution prepared from coal gasification slag as the main silicon source and sodium source. The effects of crystallization reaction time, the crystallization temperature, the Na2O/SiO2molar ratio, and the SiO2/Al2O3molar ratio on the relative crystallinity and the specific surface area of the ZSM-5 zeolite were investigated and optimized. The optical reaction conditions were as follows: a crystallization time of 12 h, a crystallization temperature of 170 °C, a Na2O/SiO2molar ratio of 0.2, and a SiO2/Al2O3molar ratio of 200. The optimal ZSM-5 zeolite synthesized is hexagonal, with regular grains, a relative crystallinity of 101.48%, a specific surface area of 337.48 m2·g−1, and a pore volume of 0.190 cm3·g−1. And the optimal ZSM-5 zeolite was composed of SiO2content of 97.52 wt%, Al2O3content of 1.58 wt%, Na2O content of 0.33 wt%, and SiO2/Al2O3molar ratio of 104.93. Na2O/SiO2molar ratio is 0.0033. The results of static adsorption experiments show that the static adsorption capacities of ZSM-5 zeolite forp-xylene, benzene, toluene, and butyl acetate were 118.85, 69.98, 68.74, and 95.85 mg·g−1, respectively, which can effectively adsorb VOCs. The synthetic process of the ZSM-5 zeolite is a simple preparation process and short in synthesis time. The results of this study not only help to realize the high-value utilization of silicon components in solid waste, but also provide an economical and effective way to synthesize VOCs adsorption materials.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2020
·Vol. 151
·期 7
·1984-1992
·
IF 2.482
Wu Ningxin,Zhang Manling,Pan Xiaomei,Zhang Jin,Gao Lijing,Xiao Guomin
Abstract The production of 5-hydroxymethylfurfural (HMF) from cellulose is of great significance for the high-value utilization of biomass, although this route currently faces the challenge of low efficiency. In the present work, a series of effective (x)Hf/ZSM-5 catalysts were developed for HMF production from cellulose, and analyzed by BET, XRD, SEM, ICP, NH 3 -TPD, Py-FTIR techniques. Driven by the (5)Hf/ZSM-5 catalyst, HMF with a yield of up to 67.5% and 17.2% of furfural are simultaneously obtained from cellulose in the H 2 O (NaCl) /THF biphasic system. Moreover, after four consecutive cycles, (5)Hf/ZSM-5 catalyst still maintained part of its catalytic activity. The 67.5% HMF yield achieved herein is one of the highest yields achieved in the conversion reaction using cellulose as a substrate, and the catalytic performance of the H 2 O (NaCl) /THF system containing the (5)Hf/ZSM-5 catalyst is even comparable to that of the expensive ionic liquid system. This result reflects the application prospect of (5)Hf/ZSM-5 catalyst in the future industrial production process of HMF. Graphic Abstract
研究领域:
化学工程
·
催化
·
生物质转化
✓ 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）