JOURNAL OF THE ENERGY INSTITUTE
·
2024
·
IF 5.6
Liwen Du,Zhongyang Luo,Kaige Wang,Feiting Miao,Qingguo Zhou,Wanchen Zhu,Longfei Li
The ex-situ catalytic pyrolysis of poplar in a dual-catalyst system of hydroxyapatite (HAP) and HZSM-5 was performed using a bench-scale device to enhance the aromatics production. Results indicated that the introduction of HAP could effectively achieve the deoxygenation of macromolecular oxygenates, which were then converted into hydrocarbon precursors. The combination of HAP and HZSM-5 exceedingly promoted the production of aromatics especially monocyclic aromatics (MAHs) than single HZSM-5. The effects of operating conditions on aromatics yield and distribution were investigated. Under the catalyst layout of mode B, with the optimum conditions reaching the catalytic temperature of 500 °C, HAP to HZSM-5 ratio of 2:4, and catalyst to biomass ratio of 1:1, the maximum aromatics yield of 9.10 wt% was achieved, accompanied by the monocyclic aromatics/polycyclic aromatics ratio enhanced to 2.33. At this point, the synergistic effect for MAHs and total aromatics reached 170.09% and 214.14%, respectively. Compared to the conventional metal oxides, the HAP/HZSM-5 dual-catalyst system exhibited superior performance in aromatics production. Besides, the anti-coking capability of HZSM-5 in the dual-catalyst system was also better than that of pure HZSM-5. This research provided a new perspective for the efficient utilization of biomass energy.
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DOI
高影响因子
Molecular Catalysis
·
2017
·
IF 0
Shuang Chu,Li’na Yang,Xingcui Guo,Linlin Dong,Xiufang Chen,Yaru Li,Xindong Mu
The catalytic behavior of a series of MFI catalysts with different Si/Al ratio (25–300) in the direct aqueous-phase hydrolysis of α-cellulose was studied. The effects ultrasonic pretreatment time, ZnCl 2 content, zeolite pore structure and acid-basic properties on catalyst activity and products distribution were systematically investigated. The results indicated that HZSM-5 with lower Si/Al ratio was beneficial for production of glucose and LA from α-cellulose. Ultrasonic pretreatment could decrease the degree of crystallinity and polymerization of α-cellulose, enhance the accessibility of acid sites and ZnCl 2 to the loosened amorphous regions of α-cellulose in water, and improve the hydrolysis efficiency of α-cellulose. The desilicated ZSM-5 (HZSM-5-DS(0.2)) showed much higher catalytic activities as compared to commercial ZSM-5 and α-cellulose conversion reached 76.5% over HZSM-5-DS(0.2) at 200 °C. Catalytic conversion of α-cellulose consisted of at least three important parallel reactions under the present hydrothermal conditions and a plausible pathway was proposed. Effective control of these reactions would be helpful to further maximize the target product yield during the catalytic conversion of α-cellulose.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2026
·
IF 9.6
Wenjing Miao,Xiaomin Liu,Bin Li,Yufeng Wu,Wei Zhang,Wei Wang
This study addresses the challenges in recycling rare earth polishing powder waste (REPPWs)—such as harsh leaching conditions, poor morphology control, and low value-added output—by proposing a synergistic “leaching-morphology control-zeolite loading” strategy. This approach enabled the successfully synthesize of flower-like Ce Ov La/HZSM-5 composite catalyst using polishing powder as the primary raw material. This strategy involves three key elements: 1) co-leaching Ce 3+ /La 3+ with a H 2 SO 4 -ascorbic acid system, 2) precisely constructing Ce Ov La with abundant oxygen vacancies (Ovs) via controlled oxalic acid addition, and 3) obtaining the final catalyst by in-situ HZSM-5 growth on the Ce Ov La. Density functional theory (DFT) calculations revealed that La doping reduced the formation energy of Ovs within the CeO 2 lattice. Moreover, the incorporation of HZSM-5 further decreased this energy barrier while also provided abundant acidic sites. The synergistic interaction between these components enhanced the electronic environment and dispersion of active sites, thereby significantly promoting C Cl bond cleavage and deep oxidation of dichloromethane (DCM). Experimental results demonstrated that the catalyst achieved 81.8% DCM conversion at 450 °C, with over 99% CO 2 selectivity and minimal Cl 2 byproduct formation. This work offers new insights into the value-added utilization of REPPWs and the efficient degradation of chlorinated volatile organic compounds (CVOCs). Download: Download high-res image (227KB) Download: Download full-size image
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PubMed
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2026
·
IF 7.8
Yongjun Zhang,Xiaodan Zhang,Yulong Zhao,Jiayu Zhang,Hongjing Han,Enhao Sun,Yanan Zhang,Yanguang Chen,Chunming Xu
La/P/HZSM-5 with multi-level pore structure was synthesized via a stepwise dual-template strategy. • The La/P/HZSM-5 zeolite reduces Brønsted acidity and creates Lewis acidity. • The optimal acidity of La/P/HZSM-5 promotes radical and monomolecular cracking. The enhancement of ethylene yield via catalytic cracking presents a persistent challenge in addressing ethylene supply shortages. A series of bifunctional catalysts (La/P/HZSM-5) were prepared via simultaneous incorporation of lanthanum and phosphorus into HZSM-5 zeolite. The Py-IR analyses revealed that the simultaneous introduction of lanthanum and phosphorus resulted in a decrease in the Brønsted acid content of the La/P/HZSM-5 catalyst from the HZSM-5 (0.792 mmol/g) to 0.223 mmol/g. Further analysis of the structure-activity relationship between the catalyst and its performance reveals that the low Brønsted acid and porous structure effectively promotes the monomolecular decomposition of the cracking process. It was evident that the synergistic modification has resulted in the La/P/HZSM-5 catalyst demonstrating superior performance in n -octane cracking, with a cracking mechanism ratio (CMR) of 49.35. The balanced metal-acid functionality of the La/P/HZSM-5 catalyst was found to result in C 2 H 4 yields of 31.23% from n -octane and 19.18% from diesel, representing increases of 31.11% and 50.20%, respectively, compared to the parent HZSM-5 (23.82% and 12.77%). The present work provided a theoretical foundation for the design of metal-acid bifunctional catalysts, with a view to improving ethylene production in catalytic cracking processes. Download: Download high-res image (260KB) Download: Download full-size image
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DOI
高影响因子
FUEL
·
2026
·
IF 7.5
Yuejin Zhan,Bi Luo,Jiaying Chen,Vasilevich Sergey Vladimirovich,Bilainu Oboirien,Qingang Xiong,Yefeng Zhou
During plastic catalytic pyrolysis, HZSM-5 faces challenges such as limited mass transfer and low active site utilization, resulting in poor aromatization and anti-deactivation performance. To address these challenges, a hollow HZSM-5 catalyst with a hierarchical micro- meso -macroporous structure was designed in this work. The structure–activity relationship of hollow HZSM-5 was then systematically explored, focusing on the influence of pore structure and acidic sites on catalytic performance. The hollow HZSM-5 catalyst without metal loading exhibited outstanding catalytic performance in the catalytic pyrolysis of plastics, with high selectivity of 95.79% for aromatic hydrocarbons (AHs) and 83.08% for monocyclic aromatic hydrocarbons (MAHs). More importantly, hollow HZSM-5 delivered outstanding stability with an initial performance retention of 95.75% after five cycles and achieved selectivity of AHs exceeding 86% for various polyolefin plastics. The excellent catalytic performance was attributed to the synergistic optimization of pore structure and acidic sites. On the one hand, the hierarchical porous structure significantly enhanced mass transfer, thereby improving the anti-deactivation performance and active site utilization of the catalyst. On the other hand, acidity enhanced by desilication efficiently promoted the aromatization of plastics. This work highlighted the importance of rational catalyst design in achieving efficient and stable catalytic pyrolysis of plastics toward valuable chemical products.
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高影响因子
FUEL PROCESSING TECHNOLOGY
·
2023
·
IF 7.5
Xiaohua Li,Haowen Fu,Shanshan Shao,Yixi Cai
Templating agents were created by utilizing several methods to handle natural cellulose (bagasse), and they were successfully used to treat HZSM-5 to introduce extra mesopores . In addition, the hierarchical HZSM-5 was employed in the catalytic pyrolysis of biomass to produce hydrocarbon fuels. The hydroxyl content in the templating agent could be promoted via hydrothermal and ultrasound-assisted treatment, improving their performance as templates to produce mesopores. The cellulose content in the templating agents was effectively boosted via hydrothermal-assisted treatment, whereas their relative crystallinity was improved by ultrasound assistance. The formation of mesopores was promoted with the increased cellulose content in the templating agents, and the catalytic performance in upgrading pyrolysis gas for aromatic hydrocarbons could be significantly improved. Higher relative crystallinity was advantageous for enhancing the stability of the templating agent in the catalyst synthesis system, and the formation of pore structures of the catalyst was promoted. Among all catalysts synthesized, catalysts synthesized by hydrothermal-assisted treatment (Cat-H(X)) presented the highest specific surface area and average pore size of 397.60 m 2 /g and 4.53 nm, which were about 1.41 and 1.98 times of commercial HZSM-5 (H-Z). The highest yield of BTX obtained with Cat-H(X) was 8.7 wt%, 1.81 times that obtained with H-Z.
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高影响因子
JOURNAL OF CATALYSIS
·
2022
·
IF 8.047
Xin-Xin Fu,Jian-Peng Li,Zhuo-Qian Li,Yan Liu,Chen-Xiao Feng,Hai-Yang Wang,Zhi-Peng Zhao,Qiao-Yun Liu,Zhong-Yi Liu,Zhi-Kun Peng
Biomass is a promising renewable carbon resource, and bio-based platform molecules such as furan derivatives play an important role in the green manufacturing of high value-added chemicals. Of these, the conversion of 2-methylfuran (2-MF) to 3-acetyl-1-propanol (3-AP) over a bifunctional catalyst has attracted significant interest. However, bifunctional catalysts prepared by traditional method suffer from poor catalytic performance and limited stability due to the agglomeration of metal NPs. Here, Pd@HZSM-5, in which Pd NPs were encapsulated in HZSM-5 in situ showed improved stability and 3-AP yield. The highest yield of 3-AP (90.6%) to date was obtained with a nearly 100% conversion of 2-MF. The catalytic performance over a series of Pd@Zeolite confirms the superiority of the encapsulation effect, which is ascribed to the optimal adjustment of metal/acid balance. The Pd@HZSM-5 catalyst displayed excellent stability due to the encapsulation structure, which restricts the Pd NPs agglomeration. The highest yield of 3-AP was obtained at a high concentration of 2-MF (60%), which implies a promising strategy for the green industrial manufacture of 3-AP. This work reports a new bifunctional catalytic system for the green synthesis of 3-AP from 2-MF, thus stimulating the downstream biomass market.
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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
BIORESOURCE TECHNOLOGY
·
2018
·
IF 5.807
Zihao Zhang,Hao Cheng,Hao Chen,Kequan Chen,Xiuyang Lu,Pingkai Ouyang,Jie Fu
Modified H-type ZSM-5 (HZSM-5) catalysts were prepared using hexadecyl trimethyl ammonium bromide (CTAB) as mesopore templates to enhance the activity for the catalytic fast pyrolysis of rice straw for aromatics compounds. A certain quantity of CTAB added into the HZSM-5 (HZ) forming hierarchical structure exhibited an improvement in the yield of the aromatics and a decrease in the yield of coke in comparison with that of bare HZ. In contrast, excessive CTAB addition resulted in a decrease in aromatic yield and an increase in coke yield. The effects of crystallinity, textural properties, morphological structure and acidity distribution on the production of aromatic compounds were measured by XRD, BET, TEM and NH 3 -TPD. The good crystallinity, small amount of mesopore formation and highest total acidity discovered in HZ-0.01 (the mole ratio of CTAB/SiO 2 is 0.01) provided the highest aromatic compound yield of 26.8% and the lowest coke yield of 39.2%.
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PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Weilun Yu,Xing You,Yuanchen Wu,Chuanpeng Li,Qiyao Wang,Xiaohang Yang,Xingbo Bian,Yi Lu
The most promising and environmentally friendly strategy to address the greenhouse effect is to utilize renewable solar energy and semiconductor photocatalytic technology to convert excessive CO₂ into valuable chemicals. However, the unsatisfactory photoreduction activity and product selectivity of pristine semiconductor remain significant barriers to their large-scale industrial application. In this study, graphitic carbon nitride (g-C 3 N 4 ) was selected as a model photocatalyst, and HZSM-5 zeolite with a high Si/Al ratio of 500 was employed to synthesize g-C 3 N 4 /HZSM-5 composite via a simple thermal polymerization method. The incorporation of HZSM-5 zeolite, characterized by its rich pore structure, significantly increased the composite's specific surface area, thereby reducing the transportation distance of photoexcited charge carriers and enhancing photoelectric conversion efficiency. The pore structure of HZSM-5 zeolite facilitated the enrichment of CO 2 , increasing the local reactant concentration. Additionally, the specific pore micro-environment exhibited a lower adsorption strength for the reduction product (CO), preventing its further conversion into undesired by-products. Furthermore, the weak acidity of the micro-environment contributed to the stabilization of intermediates, such as -HCO 3 and -COOH, promoting specific reaction pathways. As a result, the g-C 3 N 4 /HZSM-5 composite achieved high CO 2 photoreduction activity and CO selectivity (>95 %). This work highlights the potential of designing composite photocatalysts with tailored micro-environments for efficient and selective CO 2 photoreduction.
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高影响因子
FUEL
·
2025
·
IF 7.5
Binbin Chen,Hong Tian,Zhen Zhou,Yanni Xuan,Zhijie Wang,Siying Liu
A combined pretreatment of straw was carried out using acid washing and torrefaction methods. Metal-modified HZSM-5 core–shell molecular sieves were prepared by loading Zn (2, 4, and 6 wt%) and Ni (6, 8, and 10 wt%) on HZSM-5 molecular sieves and introducing MCM-41 core–shell structure. PY-GC/MS and a tubular furnace were employed to study the effects of pretreatment conditions and catalysts on the product composition distribution during wheat straw catalytic pyrolysis. XRD, SEM, BET, TPD and ICP were used to characterize the catalyst performance. It was found that the combined acid washing and torrefaction pretreatment reduced the oxygenated compounds in the bio-oil from straw catalytic pyrolysis and increased the bio-oil yield to 29.37 %. The incorporation of modified catalysts promoted the deoxygenation, zwitterionization and aromatization reactions during the straw-catalyzed pyrolysis. The monometallic loading of 4%Zn/HZ and 8%Ni/HZ catalyzed acid washing and torrefaction straw pyrolysis resulted in 54.2 % and 57.06 % yields of MAHs and 42.86 % and 38.58 % yields of BTX in bio-oil, respectively.Compared with the monometallic loading, 4%Zn8%Ni/HZ further optimized the bio-oil compositional distribution, with a MAHs yield of 64.76 %, a BTX yield of 54.69 %, and a deoxygenation performance of 81.34%.MCM-41-coated HZSM-5 produces a large mesoporous structure with channels with sufficient transport capacity, accelerating the cleavage of various types of oxygen-containing compounds in the bio-oil into smaller molecules for better conversion into aromatics. The 4%Zn8%Ni/H@M catalyst achieved a MAHs yield of 72.68 % and BTX yield of 63.43 % in the bio-oil during pyrolysis of acid-washed and torrefied wheat straw, with oxygen removal efficiency reaching 85.37 %. Therefore, the combination of feedstock pretreatment and metal-modified core–shell HZSM-5 molecular sieve could synergistically optimize both compositional distribution and production yield of bio-oil derived from biomass pyrolysis.
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高影响因子
ACS Sustainable Chemistry & Engineering
·
2017
·
IF 5.951
Jia Ding,Pengjing Chen,Songyu Fan,Zhiqiang Zhang,Lupeng Han,Guofeng Zhao,Ye Liu,Yong Lu
Free-standing stainless-steel (SS)-fiber@meso-HZSM-5 core–shell catalysts engineered from micro- to macro-scale were highly efficiently synthesized via cost-effective steam-assisted crystallization (SAC) method. Impact of synthesis conditions on their morphology and textural/acidic properties was investigated by means of XRD, SEM, TEM, solid-state NMR, NH3-TPD, Py-IR and N2 physisorption. Single-run lifetime of such structured catalysts for MTP process was strongly dependent on their preparation conditions but slightly the product distribution. A volcano-like relationship for lifetime was observed against the SAC time, which was correlated well with the crystallization-time-dependent crystallinity, mesoporosity and crystal size. The promising SS-fiber@meso-HZSM-5 was the one obtained after the SAC for 12 h, which delivered a prolonged single-run lifetime of 620 h with a high propylene selectivity of ∼42% at 450 °C using a methanol weight hourly space velocity (WHSV) of 1 h–1, as the result of high crystallinity, well-developed mesoporosity and small crystal size. Note that well-developed mesoporosity was paramount for the catalyst stability improvement, because of enhanced accommodation capacity of zeolite shell for receiving formed coke.
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高影响因子
危险品化学品经营许可证（带存储）