INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2025
·
IF 3.9
Feng Wang,Yimin Zhang,Xinyu Xu,Yunxiang Nie,Binbin He,Yi Mei,Yun Zu
Low-valuable utilization and a massive accumulation of yellow phosphorus slag (YPS) have caused severe pollution in surrounding environments. Among numerous implementation strategies, the conversion of YPS into phosphorus-containing zeolites represents a promising approach for high value-added utilization. Herein, we report that P-ZSM-5 zeolites were successfully prepared from acid-leaching YPS in one step using a hydrothermal synthesis method. The obtained P-ZSM-5 zeolites exhibited high crystallinity, uniform crystal size (200–400 nm), and a large BET surface area (>400 m2/g). Accordingly, a nonclassical crystallization mechanism of P-ZSM-5 zeolites from the YPS was proposed by multiple advanced characterizations. Importantly, the presence of phosphorus not only induced framework Al sited in the straight/sinusoidal channels and improved the hydrothermal stability of the zeolite framework but also enhanced the Brønsted acidity. Under comparable conditions, the as-prepared P-ZSM-5(75) zeolite catalyst with a higher ratio of Brønsted/Lewis acid sites in the methanol-to-propylene reaction exhibited a considerable catalytic lifetime (30 h, WHSV = 6 h–1), high propylene selectivity (55.1%), and a propylene-to-ethylene ratio of 5.9. The advancement in P-ZSM-5 zeolites paves a novel way for more effective YPS utilization and driving sustainability in phosphorus-based chemical production.
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高影响因子
CHINESE JOURNAL OF CATALYSIS
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2018
·
IF 3.525
Wenjin Xu,Guangxu Zhang,Hanwei Chen,Guomeng Zhang,Yang Han,Yichuan Chang,Peng Gong
Two series of Mn/beta and Mn/ZSM-5 catalysts were prepared to study the influence of how different Mn precursors, introduced to the respective parent zeolites by wet impregnation, affected the selective catalytic reduction (SCR) of NO by NH 3 across a low reaction temperature window of 50–350 °C. In this study, the catalysts were characterized using N 2 adsorption/desorption, X-ray diffraction, X-ray fluorescence, H 2 temperature-programmed reduction, NH 3 temperature-programmed desorption and X-ray photoelectron spectroscopy. As the manganese chloride precursor only partially decomposed this primarily resulted in the formation of MnCl 2 in addition to the presence of low levels of crystalline Mn 3 O 4 , which resulted in poor catalytic performance. However, the manganese nitrate precursor formed crystalline MnO 2 as the major phase in addition to a minor presence of unconverted Mn-nitrate. Furthermore, manganese acetate resulted principally in a mixture of amorphous Mn 2 O 3 and MnO 2 , and crystalline Mn 3 O 4 . From all the catalysts screened, the test performance data showed Mn/beta-Ac to exhibit the highest NO conversion (97.5%) at 240 °C, which remained >90% across a temperature window of 220–350 °C. The excellent catalytic performance was ascribed to the enrichment of highly dispersed MnO x (Mn 2 O 3 and MnO 2 ) species that act as the active phase in the NH 3 -SCR process. Furthermore, together with a suitable amount of weakly acidic centers, higher concentration of surface manganese and a greater presence of surface labile oxygen groups, SCR performance was collectively enhanced at low temperature.
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BIORESOURCE TECHNOLOGY
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2022
·
IF 11.889
Yingyuan Wei,Sandile Fakudze,Yu Zhang,Min Song,Tianjiao Xue,Ruiyan Xie,Jianqiang Chen
Ionic liquid loaded ZSM-5 with high stability and catalytic performance was used for hydrothermal liquefaction (HTL) of pomelo peel for the first time. Bio-oil obtained at 200 °C had the highest yield (29.21 wt%) and high heating value (21.41 MJ/kg), with main constituents of 5-hydroxymethylfurfural (5-HMF, 50.10%), 3-Pyridinol (19.8%) and pentanoic acid (5.35%). The higher 5-hydroxymethylfurfural yield obtained using ionic liquid loaded ZSM-5 was further compared to other studies (0–50%). In comparison to high-temperature HTL, catalytic HTL with ionic liquid loaded ZSM-5 led to lower activation energy requirements (31.93 kJ·mol −1 ) for the conversion of glucose into 5-HMF. Additionally, the catalysts showed excellent recyclability, with 19.68 wt% of bio-oil containing 59.6% of light oil obtained after 5 cycles. Hence, this study presents a novel approach for the catalytic conversion of lignocellulosic biomass into 5-HMF-rich bio-oil for energy and green chemistry applications.
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PubMed
高影响因子
Catalysis Science & Technology
·
2016
·Vol. 6
·期 8
·2647-2652
·
IF 5.287
Hualei Hu,Jinghui Lyu,Jiayao Rui,Jie Cen,Qunfeng Zhang,Qingtao Wang,Wenwen Han,Xiaonian Li
Ethylbenzene is the major side product in benzene alkylation with methanol and it is difficult to be suppressed over hierarchical porous ZSM-5. Moreover, the separation of ethylbenzene from xylene still remains a great challenge. Our research indicated that ethylbenzene formation could be highly suppressed by changing the Si/Al ratio of the catalyst. Hierarchical porous ZSM-5 catalysts with different Si/Al ratios were prepared via reducing the amount of Al in the solvent evaporation assisted dry gel conversion method. In this method, tetra-n-propylammonium hydroxide was used as the direct agent to create micropores, and hexadecyltrimethoxysilane was added to create additional porosities by forming organic assemblies which occupied a certain space between zeolitic walls. The catalyst with a Si/Al ratio of 1800 could achieve high benzene conversion (59.5%) and high xylene selectivity (39.0%) as well as excellent suppression of ethylbenzene formation (<0.1%).
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高影响因子
Catalysts
·
2021
·Vol. 11
·期 3
·324
·
IF 4.146
Jinkun Guan,Lusha Zhou,Weiquan Li,Die Hu,Jie Wen,Bichun Huang
SO2poisoning is a great challenge for the practical application of Mn-based catalysts in low-temperature selective catalytic reduction (SCR) reactions of NOxwith NH3. A series of Gadolinium (Gd)-modified MnOx/ZSM-5 catalysts were synthesized via a citric acid–ethanol dispersion method and evaluated by low-temperature NH3-SCR. Among them, the GdMn/Z-0.3 catalyst with the molar ratio of Gd/Mn of 0.3 presented the highest catalytic activity, in which a 100% NO conversion could be obtained in the temperature range of 120–240 °C. Furthermore, GdMn/Z-0.3 exhibited good SO2resistance compared with Mn/Z in the presence of 100 ppm SO2. The results of Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction of H2(H2-TPR) and temperature-programmed desorption of NH3(NH3-TPD) illustrated that such catalytic performance was mainly caused by large surface area, abundant Mn4+and surface chemisorbed oxygen species, strong reducibility and the suitable acidity of the catalyst. The in situ diffuse reflectance infrared Fourier transform spectra (DRIFTS) results revealed that the addition of Gd greatly inhibited the reaction between the SO2and MnOxactive sites to form bulk manganese sulfate, thus contributing to high SO2resistance. Moreover, in situ DRIFTS experiments also shed light on the mechanism of low-temperature SCR reactions over Mn/Z and GdMn/Z-0.3, which both followed the Langmuir–Hinshelwood (L–H) and Eley–Rideal (E–R) mechanism.Keywords:SO2poisoning;low temperature;NH3-SCR;in situ DRIFTS
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高影响因子
FUEL
·
2019
·
IF 5.128
Chengchao Liu,Yao Chen,Yanxi Zhao,Shuai Lyu,Liang Wei,Xin Li,Yuhua Zhang,Jinlin Li
ZSM-5 zeolite is usually used to modify the product selectivity for Fischer–Tropsch synthesis (FTS). Here, we prepared a nano-ZSM-5 zeolite with a particle size of 80 nm. This zeolite was used as a support to prepare bifunctional Co-based FTS catalysts by incipient wetness impregnation [using water as a solvent (W-Co/H-ZSM-5) or alcohol as a solvent (A-Co/H-ZSM-5)] and an ultrasound-assisted impregnation method (U-Co/H-ZSM-5). These catalysts were characterized by X-ray diffraction (XRD), N 2 -physical absorption, H 2 temperature-programmed reduction (H 2 -TPR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The FTS catalytic performances of all catalysts were compared in a fixed-bed reactor. Characterization data revealed that the U-Co/H-ZSM-5 catalyst had the best cobalt dispersion, resulting in the most stable CO conversion. Moreover, the nanoscale relationship between the activity and acid sites enhances the hydrocracking ability, increasing the liquid fuel selectivity from 49.7% to 67.8% (no C 20+ product was detected for U-Co/H-ZSM-5) for a reaction at 503 K. In addition, the CH 4 selectivity increases as the reaction temperature increases from 483 K to 513 K, which is beneficial for producing liquid fuel products (67.8%) at a reaction temperature of 503 K.
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高影响因子
FUEL
·
2022
·
IF 8.035
Yan Cui,Bin Chen,Leilei Xu,Mindong Chen,Cai-e Wu,Jian Qiu,Ge Cheng,Ning Wang,Jingxin Xu,Xun Hu
Hollow ZSM-5 zeolites prepared using different alkaline solutions were employed as Ni based catalyst supports for the methanation of CO 2 . The catalysts were thoroughly characterized, and in-situ DRIFTS were used to study the CO 2 methanation intermediates. Using the hollow Ni-based catalysts led to enhanced CO 2 conversion as well as CH 4 selectivity compared with the traditional Ni/ZSM-5, which was mainly due to the strong basicity of the hollow supports as well as the presence of silicon hydroxyls. Meanwhile, the 15Ni/H-ZSM-5-T catalyst prepared with TPAOH solution had higher catalytic performance than 15Ni/H-ZSM-5-NT and 15Ni/H-ZSM-5-N. The introduction of the hollow zeolite morphology led to enhanced diffusion behavior in the catalyst, which inhibited catalyst deactivation. Therefore, the hollow structure of the support with alkaline treatment was an important consideration for the design and preparation of high-performance Ni-based catalysts for CO 2 methanation.
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高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2023
·
IF 3.4
Guoliang Zhang,Haoyu Liu,Sen Fu,Hong Yuan
BACKGROUND A series of ZSM-5@KIT-6 composite molecular sieve catalysts was prepared by encapsulating ZSM-5 as a substrate in the mesoporous material KIT-6. The intent was to use these catalysts to promote the catalytic cracking of a waste cooking oil model compound (WCOMC) to produce light olefins. RESULTS The morphology, structural characteristics and acidity of each of the resulting catalysts were characterized by X-ray diffraction, transmission electron microscopy, N 2 -Brunauer–Emmett–Teller (N 2 -BET) surface area analysis and temperature-programmed ammonia desorption. The results showed that ZSM-5 was successfully coated with KIT-6. The BET surface areas of these catalysts ranged from 345 to 792 m 2 g −1 and the specimens had average pore sizes in the range of 2.37–5.51 nm. Total acidity increased with increases in the mass-based proportion of ZSM-5 in the material. CONCLUSION The catalytic cracking of WCOMC was studied in a lab-scale fixed-bed apparatus. Trials at a reaction temperature of 600 °C using the material having a mass-based ZSM-5 proportion of 80.0% (ZK-80) gave the highest gas-phase yield of light olefins of 43.8%. After 6000 min, the catalytic performance of this material remained stable, demonstrating a resistance to carbon deposits. The superior activity of the present composite catalysts can be ascribed to improvements in pore structure and acid strength distribution. © 2023 Society of Chemical Industry (SCI).
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高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2014
·Vol. 16
·期 12
·1-11
·
IF 2.278
Sang Yu,Jiao Qingze,Li Hansheng,Wu Qin,Zhao Yun,Sun Kening
A series of HZSM-5/MCM-41 composite molecular sieves (HZM-Ns ( x )) were prepared by employing nano-ZSM-5 zeolites with the SiO 2 /Al 2 O 3 ratios ( x ) of 50, 100 and 150 as the source. These materials were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy, N 2 adsorption–desorption measurement, and NH 3 temperature-programmed desorption. The catalytic cracking of endothermic hydrocarbon fuels over the HZM-Ns with n -decane as model was evaluated at atmospheric pressure and 500 °C. The effect of the parent zeolite, mesopore and SiO 2 /Al 2 O 3 ratio on the structure, acidity, and catalytic performance of HZM-Ns was investigated. The HZM-Ns exhibited a skeletal matrix with nano-sized HZSM-5 particles (200–300 nm) with a controllable acidity well dispersed in and microporous–mesoporous hierarchical pores. The mesoporous structure improved the diffusion of the reactants and products in the pores, and the HZSM-5 nanoparticles uniformly dispersed in the MCM-41 matrix supplied a proper acidity, shorter channels, and a higher specific surface area for reaction. These resulted in a high catalytic activity, a high selectivity to light olefins and a long lifetime for n -decane catalytic cracking. The HZM-N (150) exhibited the excellent conversion, a high selectivity to light olefins and a long lifetime due to low diffusion resistance, high specific surface area, and appropriate acid distribution and strength, with the increasing SiO 2 /Al 2 O 3 ratio.
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高影响因子
Catalysts
·
2023
·Vol. 13
·期 7
·1080
·
IF 3.9
Shiyuan Lin,Ruosong He,Wenhang Wang,Yang Wang,Yongqiang Gu,Qiang Liu,Mingbo Wu
The abundant C1 source CO2can be utilized to produce value-added chemicals through hydrogenation technology. A bifunctional catalyst consisting of reducible metal oxide Cr2O3and acidic zeolite ZSM-5 was designed for the direct conversion of CO2+ H2into valuable aromatics, especially para-xylene (PX), via the methanol-mediated pathway. The twin structure of ZSM-5 (ZSM-5T), with sinusoidal channels that are predominantly exposed to the external surface, enhances the possibility of the transformation of methanol into PX due to the favorable diffusion dynamic of PX in the sinusoidal channels. Via the bifunctional catalyst Cr2O3&ZSM-5T, a PX selectivity of 28.7% and PX space-time yield (STY) of 2.5 gCH2h−1kgcat−1are achieved at a CO2conversion rate of 16.5%. Furthermore, we rationally modify the ZSM-5Tzeolite via Cu species doping and amorphous SiO2shell coating (Cu-ZSM-5T@SiO2). After combining with the Cr2O3catalytic component, the CO2conversion (18.4%) and PX selectivity (33.8%) are increased to some extent, which systematically increases the STY of PX to 3.0 gCH2h−1kgcat−1. The physicochemical property of the acidic zeolite and the corresponding structure-function relationship in enhancing the PX productivity are discovered. Our work provides a novel catalyst design idea to boost PX synthesis performance from CO2hydrogenation.Keywords:CO2hydrogenation;bifunctional catalysts;para-xylene;H-ZSM-5 zeolites
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高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2023
·
IF 5.2
Xinyu Li,Shunyu Han,Jingzhe Xu,Nanzhe Jiang
The synthesis of zeolites from natural aluminosilicate minerals is environmentally sustainable. However, the preparation of nano-ZSM-5 zeolite single crystals via the facile “silica–alumina homologation” of natural clay remains challenging. This paper highlights a novel strategy for the synthesis of defect-free, highly crystalline nano-H-ZSM-5 with a uniform morphology through the kinetically controlled in situ reconstruction of the topology of natural clay within a solid-state-like system. Crystal nucleation and growth were decoupled by aging to control the crystal size. The “homogeneous silica–alumina” property of natural clay was found to be directly inherited by nano-H-ZSM-5 to provide uniformly distributed acidic sites for catalysis. This was demonstrated by methanol-to-propylene conversion, wherein the performance of the obtained crystals was superior to that of commercial ZSM-5. This strategy promotes the development of natural silica–aluminate clay resources and allows the scalable production of high-quality nano-H-ZSM-5 single crystals for heterogeneous catalysis .
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高影响因子
JOURNAL OF POROUS MATERIALS
·
2018
·Vol. 25
·期 6
·1587-1595
·
IF 1.858
Shen Yu,Wang Fumin,Liu Wei,Zhang Xubin
A series of Fe 3+ containing catalysts were synthesized using ion-exchange technique over hierarchically porous ZSM-5 (M-ZSM-5) and micro-mesoporous composite ZSM-5/MCM-41 (ZSM-5/MCM-41), respectively. The prepared catalysts were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, N 2 adsorption–desorption, UV–Vis spectroscopy, temperature programmed reduction and inductively coupled plasma-optical emission spectroscopy. The characterization results exhibit that the hierarchically porous ZSM-5 was synthesized with intracrystalline mesopores, while the micro-mesoporous composite ZSM-5/MCM-41 was prepared with the well-ordered mesopores. Furthermore, the results also prove that the existence of iron in the catalysts was mainly presented in the form of Fe 3+ ions. Catalytic performances of the samples for phenol hydroxylation were compared by using H 2 O 2 as oxidant. Under the optimized conditions, Fe 3+ ion-exchanged M-ZSM-5 (Fe-M-ZSM-5) shows that a phenol conversion of 42.3% obtained with 92.5% selectivity to dihydroxybenzenes, whereas Fe 3+ ion-exchanged ZSM-5/MCM-41 (Fe-ZSM-5/MCM-41) give 46.2% phenol conversion and 90.1% dihydroxybenzenes selectivity, which are all better than most reported results. The recyclability tests show that Fe-ZSM-5/MCM-41 with ordered mesoporous structure and bigger surface area has better anti-deactivation performance than Fe-M-ZSM-5. The excellent catalytic performances were due to the improved diffusion performance with newly created mesopores and the highly active Fe 3+ species obtained by ion-exchange technique.
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高影响因子
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