Catalysis Science & Technology
·
2016
·Vol. 6
·期 12
·4260-4270
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IF 5.287
He Huang,Chuanhui Zhang,Lei Wang,Genqin Li,Liang Song,Guangci Li,Sifu Tang,Xuebing Li
A series of HZSM-5 supported MnOx catalysts with different manganese contents were prepared by an incipient impregnation method and tested for the catalytic oxidation of toluene. The catalytic results indicate that 10% MnOx/HZSM-5 exhibits the optimum catalytic activity, excellent catalytic durability in dry conditions and high regeneration capability in humid conditions. The dispersion of MnOx species on the HZSM-5 surface significantly reduces coke formation and simultaneously efficiently accelerates the oxidative decomposition of coke deposition during toluene catalytic oxidation. An obvious cooperative action is present on the MnOx/HZSM-5 catalysts for the catalytic oxidation of toluene, which is originally attributed to the excellent toluene adsorption capacity and trapping ability of HZSM-5 as well as the superior redox ability of the MnOx species. The correlation between characterizations and the catalytic results reveals that the mesoporous structure and low-temperature reducibility of MnOx are key factors responsible for the catalytic performance of toluene oxidation. Moreover, the Brønsted acid sites of the HZSM-5 zeolite, as active promoters, play a significant role in the catalytic oxidation of toluene through a comparative analysis with SiO2 and Al2O3 supported MnOx catalysts. The existence of a cooperative action between the redox ability of the MnOx species and the acidic properties of the HZSM-5 zeolite in the MnOx/HZSM-5 catalysts results in a high catalytic activity for the reaction.
研究领域:
催化化学
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环境科学
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材料科学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Changcheng Sun,Lyumeng Ye,Peng Lu,Xianhui Yan,Jianhang Huang,Zhixiong Tang,Dongyao Chen,Chaoping Cen
The key point to broaden the operating temperature window for synergistic control of NO x and oxygenated volatile organic compounds (OVOCs) with high NO x /VOCs conversion and N 2 /CO 2 selectivity relies on development of appropriate catalysts. Herein, a silver-modified Mn/HZSM-5 catalyst was designed, which achieved an effective NO x and acetone co-removal activity and maintained over 90 % N 2 /CO 2 selectivity at a broad temperature range from 293 to 400 °C. The excellent performance of MnAg/HZSM-5 was due to large surface area, plenty of oxygen vacancies and Lewis acid sites, as well as outstanding oxygen mobility and reducibility that derived from the interactions between Mn 4+ /Mn 3+ and Ag + /Ag 0 . NO x reduction followed both Eley-Rideal and Langmuir-Hinshelwood mechanisms, while acetone hardly replaced NH 3 as a reduction agent. Acetone oxidation underwent acetone → acetate → formate → carbonate → CO 2 and H 2 O following a Mars-van Krevelen mechanism. NH 3 participated in acetone oxidation, forming amide and nitrile species, which caused catalyst deactivation and secondary pollution.
研究领域:
环境科学
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催化化学
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产品关联
DOI
高影响因子
Molecular Catalysis
·
2019
·
IF 2.938
Chenglong Dong,Hongtao Wang,Haochen Du,Jiebang Peng,Yang Cai,Shuai Guo,Jianli Zhang,Chanatip Samart,Mingyue Ding
Furfurylamine converted from biomass-based platform molecules furfural was proven a significant intermediate in the synthesis of different valuable compounds. The combination of Ruthenium with HZSM-5 was acted as an excellent selective and reusable catalyst for the reduction amination of furfural with environmentally friendly ammonia and hydrogen. Incorporation of Ru species into HZSM-5 had a significant enhancement to the acid sites of Ru/HZSM-5. The Ru/HZSM-5(46) catalyst with optimized acid sites and interaction of the Ru-O-Al bond displayed an excellent catalytic performance, producing 76 % yield of furfurylamine at only 15 min, and could be recycled five times without loss of performance. Synergistic effect between RuO 2 and metallic Ru in the Ru/HZSM-5 catalyst facilitated the reduction amination of furfural.
研究领域:
催化
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化学工程
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可持续化学
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绿色化学
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产品关联
DOI
高影响因子
ENERGY & FUELS
·
2024
·
IF 5.2
Jia-yuan Tian,Jun Hu,Feng Lin,Yu-long Ma,Yong-gang Sun,Ying-bo Zhu,Jin-peng Wei,Yi-ting Lei,Jing-jing Wu
The catalytic selective hydrodeoxygenation of guaiacol to value-added cyclohexane is one of the sustainable biomass utilization pathways for which the Ru/HZSM-5 support catalyst has been considered as promising. However, the effect of the catalyst morphology on the catalytic properties must be further investigated. Four Ru catalysts with different support morphologies, two-dimensional nanosheets (Ru/HZSM-5-P), brick-shaped (Ru/HZSM-5-G), cross-shaped (Ru/HZSM-5-J), and irregular particles (Ru/HZSM-5-D), were prepared by the impregnation method to investigate the effects of catalyst morphology and acidity on the conversion efficiency of lignin-derived guaiacol to cyclohexane. The catalytic activity data showed that Ru/HZSM-5-P exhibited the best catalytic performance among the four catalysts with a conversion rate of 99.9% for guaiacol and a yield of 99.9% for cyclohexane. The characterization results showed significant differences among the four catalysts in terms of accessibility (thickness and pore volume), acidity, metal particle size, and reduction temperature. The Ru/HZSM-5-P catalyst with a two-dimensional nanosheet structure showed the best accessibility, smaller metal particle size, reasonable metal–support interaction, and appropriate B/L. The relatively strong acid centers facilitate the activation of C–C and C–O bonds. Besides, the reduced Ru species on the Ru/ZSM-5 catalyst exhibited high H2 adsorption activity, which was beneficial for the adsorption of guaiacol. This indicates that the difference in catalyst morphology could greatly affect its catalytic activity, thereby altering the conversion rate of reactants and selectivity of the products.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL PHYSICS
·
2021
·Vol. 34
·期 1
·102-111
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IF 1.114
Qian Si-yu,Feng Bei-bei,Zhai Yi-tong,Zhao Wei,Wang Lei,Ao Cheng-cheng,Liu Yi,Liu Jing,Zhang Li-dong
To obtain insight into the catalytic reaction mechanism of biodiesels over ZSM-5 zeolites, the pyrolysis and catalytic pyrolysis of methyl butanoate, a biodiesel surrogate, with H-type ZSM-5 (HZSM-5) were performed in a flow re-actor under atmospheric pressure. The pyrolysis products were identified and quantified using gas chromatography-mass spectrometry (GC-MS). Kinetic modelling and experimental results revealed that H-atom abstraction in the gas phase was the primary pathway for methyl butanoate decomposition during pyrolysis, but dissociating to ketene and methanol over HZSM-5 was the primary pathway for methyl butanoate consumption during catalytic pyrolysis. The initial decomposition temperature of methyl butanoate was reduced by approximately 300 K over HZSM-5 compared to that for the uncatalyzed reaction. In addition, the apparent activation energies of methyl butanoate under catalytic pyrolysis and homogeneous pyrolysis conditions were obtained using the Arrhenius equation. The significantly reduced apparent activation energy confirmed the catalytic performance of HZSM-5 for methyl butanoate pyrolysis. The activation temperature may also affect some catalytic properties of HZSM-5. Overall, this study can be used to guide subsequent catalytic combustion for practical biodiesel fuels.
研究领域:
能源科学
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催化化学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2021
·
IF 13.273
Peng Lu,Lyumeng Ye,Xianhui Yan,Ping Fang,Xiongbo Chen,Dingsheng Chen,Chaoping Cen
Increasing attentions have been drawn towards the simultaneous removal of toluene in current existing NH 3 -SCR unit. The development of dual-functional catalysts and the understanding of impact induced by toluene addition are momentous but lacking. Herein, a well-reported MnO x -CeO 2 catalyst was chosen as active phase to assess the role of HZSM-5 in this simultaneous removal process. HZSM-5 was found to supply more acid sites especially Lewis acid on the MnO x -CeO 2 catalyst. A MnCe/HZSM-5 catalyst with a SiO 2 /Al 2 O 3 molar ratio of 25 delivered a broad active temperature window of 200–400 °C with NO conversion > 80% and possessed a stable N 2 selectivity > 96% in NH 3 -SCR reaction. Also, it was able to maintain above 60% of toluene conversion in the range of 200–400 °C. More Lewis acid sites, together with abundant Mn 4+ , Ce 3+ and active surface oxygen that formed via the interaction between Mn 4+ /Mn 3+ and Ce 4+ /Ce 3+ (Mn 3+ + Ce 4+ ↔ Mn 4+ + Ce 3+ ), contributed to the superior catalytic performance of MnCe/HZSM-5 with lower SiO 2 /Al 2 O 3 ratio. A reversible catalyst deactivation in NH 3 -SCR induced by toluene was found. Toluene was prone to reacting with NH 3 forming nitriles, which infringed the active sites and decreased the available coordinated NH 3 on Lewis acid sites. In addition, the suppression of NO oxidation to NO 2 that decreasing the percentage of “fast SCR” process, and the inhibition of NH 3 activation to NH 2 species also contributed to the lower SCR activity in the presence of toluene over MnCe/HZSM-5.
研究领域:
环境科学
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催化化学
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产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2023
·
IF 22.1
Kezhen Qian,Wenmin Tian,Lijie Yin,Zixu Yang,Feixiang Tian,Dezhen Chen
The nature of Zn species and their roles in catalytic cracking of high-density polyethylene (HDPE) thermal decomposing vapor over Zn-promoted HZSM-5 (Zn/Z5) for aromatics were investigated. The Zn/Z5 zeolites were prepared using ion exchange and impregnation methods followed by H 2 reduction. Results indicated that hydrogen reduction of the Zn/Z5 significantly improved the aromatic yield. [ZnOH] + and bridged Zn 2+ species were critical species promoting BTX formation, with the former demonstrating higher activity. Besides, the synergistic effect between the Zn species and Brønsted acid sites on HZSM-5 boosts the aromatic yield. Incorporation of Zn was also found to promote long-chain scission. Among all the Zn/Z5, hydrogen reduced 2 wt% Zn/Z5 (SAR=25) is most effective in producing BTX, with a maximum yield of BTX (48%) and BTX selectivity (93%); hydrogen reduced 2 wt% Zn/Z5 (SAR=50) produced the highest yield of total aromatics (53%).
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 89
·86034-86042
·
IF 3.289
Lujiang Xu,Qian Yao,Ying Zhang,Yao Fu
In this study, nano-sized HZSM-5 catalysts with different Si/Al ratios were synthesized and employed for producing pyridines from glycerol via a thermo-catalytic conversion and ammonization (TCC-A) process. The catalytic performance of micro-sized HZSM-5 and nano-sized HZSM-5 was studied firstly. The nano-sized HZSM-5 showed better catalytic performance in pyridine production in the TCC-A process due to its smaller particle size. When the nano-sized HZSM-5 (Si/Al = 25) served as the catalyst, and the reaction temperature was about 550 °C with the weight hourly space velocity of glycerol to catalyst at 1 h−1 and the ammonia to glycerol ratio at 12 : 1, the highest yield of pyridines was up to 42.1%, which was much higher than that when using micro-sized HZSM-5 (35.6%) reported before. In addition, nano-sized HZSM-5 also showed a better catalytic performance than micro-sized HZSM-5 in the catalytic conversion of bio-derived furans to produce indoles. After five reaction/regeneration cycles, the catalytic performance of nano-sized HZSM-5 slightly decreased compared with the first run, but was still higher than that of micro-sized HZSM-5.
研究领域:
化学工程
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催化材料
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产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2020
·
IF 7.1
Boxuan Yang,Zheng Zhang,Chen Tian,Wenjing Yuan,Zhongqiu Hua,Shurui Fan,Yi Wu,Xuemin Tian
Gas sensors based on Pd-loaded SnO 2 were prepared with printed zeolite films on the top of the sensor layer to enhance selective response to methane. As expected, Pd-loaded SnO 2 has a sensitive response to CH 4 and VOCs, such as ethanol and acetone vapors. Pt catalyst was dispersed onto the surface to promote the catalytic activity of zeolite. According to the catalytic characterizations, it was indicated that interfered gases, CO and ethanol were catalytically oxidized into CO 2 and water vapor. Whereas the catalytic combustion of methane is a negligible and sensitive response to the interested analyte was significantly promoted. Thus, the selective response to CH 4 was greatly improved even in a mixture of CO and VOCs. Based on the power-law response to oxygen, it was found that the resistive responses of all sensors were highly oxygen-dependent, suggesting that oxygen adsorbates on the surface were involved in the sensing process and no difference with zeolite coated sensors. Thus, it can be concluded that zeolite films printed onto the sensing layer surface serve as a catalytic filter and responsible for the enhanced sensitive and selective response of methane.
研究领域:
材料科学
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环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2025
·Vol. 15
·期 10
·751
·
IF 4.3
Jian Li,Laizhi Sun,Derun Hua,Xinning Lu,Dandan Yang,Zhiying Wu
Gallium-modified Zeolite Socony Mobil-5 (ZSM-5) zeolites were synthesized using wetness impregnation and hydrothermal synthesis methods. The structural and acidic properties of the zeolites were characterized through an analytical instrument, which demonstrated that Gallium-modified HZSM-5 zeolites retain the Mobil five instructure (MFI) framework structure, but exhibit a reduction in Brønsted acid sites and a decrease in micropore size. The catalytic performance of these zeolites in the pyrolysis of cellulose biomass and polyethylene was tested. Compared with HZSM-5, Ga-modified HZSM-5 zeolites considerably increased monoaromatic yields while reducing alkanes production. In particular, gallium-impregnated HZSM-5 increased the monoaromatic yield from 37.6% for ZSM-5 to 43.2%, while hydrothermal synthesized Ga-HMFI reduced polyaromatic and alkane yields from 6.6% and 24.6% for HZSM-5 to 2.9% and 11.4%, respectively. These results indicated that Ga-modified HZSM-5 zeolites can improve the synergy between cellulose-derived oxygenates and polyethylene-derived olefins, enhancing the yield of petrochemical hydrocarbons compared to that predicted by theoretical calculations.
研究领域:
化学工程
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能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysts
·
2018
·Vol. 8
·期 2
·82
·
IF 3.465
Yadong Bi,Xiaojuan Lei,Guihua Xu,Hui Chen,Jianli Hu
The hierarchical HZSM-5 and Hβ zeolites were prepared by alkaline post-treatment methods adopting Na2CO3, TMAOH/NaOH mixture, and NaOH as desilication sources, respectively. More mesopores are produced over two kinds of zeolites, while the micropores portion is well preserved. The mesopores formed in hierarchical Hβ zeolites were directly related to the basicity of the alkaline solution, indicating that Hβ zeolite is more sensitive to the alkaline post-treatment. The hierarchical HZSM-5 and Hβ zeolites are more active than the parent one for catalytic fast pyrolysis (CFP) of Kraft lignin. Hierarchical zeolites retained the function of acid catalysis, while additionally creating larger mesopores to ensure the entry of bulkier reactant molecules. The increase of the condensable volatiles yield can be attributed to the improvement of the mass transfer performance, which correlates well with the change of mesoporous surface area. In particular, the condensable volatiles yield for the optimized hierarchical Hβ reached approximately two times that of the parent Hβ zeolites. In contrast to the parent HZSM-5, the optimized hierarchical HZSM-5 zeolite significantly reduced the selectivity of oxygenates from 27.2% to 3.3%.Keywords:catalytic fast pyrolysis;Kraft lignin;hierarchical zeolites;HZSM-5;Hβ
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2023
·
IF 2.8
Zhang Yakun,Xu Lin,Wang Wen,Wu Qing,Zhang Yi
The efficient conversion of ethane has attracted more and more attention because of the shale gas revolution. The coupling of ethane dehydrogenation (EDH) and benzene alkylation over the 1.5Pt/HZSM-5 realize high activity close to the thermodynamic equilibrium of EDH at 500 ℃ and 0.9 bar ethane partial pressure. Meanwhile, the coupled reaction shows long-term stability during 22 h with a slightly decreased ethane conversion of 0.03% per hour and as high as 42% selectivity of ethylbenzene. Based on various characterization, including XRD, HR-TEM, NH 3 -TPD, Py-IR, TGA, it is confirmed that the coupling reaction could convert ethylene, formed by EDH over Pt sites, to ethylbenzene via benzene alkylation over Brönsted acidic sites (BAS) subsequently, and suppressing the sintering of Pt species and coke deposition induced by aromatization and deep dehydrogenation, resulting in high activity and long-time steady state. Graphical Abstract
研究领域:
化学工程
·
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）