MATERIALS CHEMISTRY AND PHYSICS
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2022
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IF 4.778
Haotian Guo,Xinhuan Lu,Jie He,Huaxin Zhang,Haifu Zhang,Yanhong Dong,Dan Zhou,Qinghua Xia
A composite material ZSM-5@Co-MOF containing Co-MOF and ZSM-5 was successfully prepared by steam-assisted crystallization of Co-MOF on the zeolite surface. Compared to physically mixing Co-MOF on the zeolite surfaces, Co-MOF nanosheets were uniformly attached to external surfaces of the ZSM-5 crystals because of the enhanced interaction between zeolite and Co-MOF in the composite. In addition, the Co-MOF was distributed as a nanosheet structure, and its dispersibility was greatly enhanced, in which this behavior led to more uniform distribution of the deposited active sites. Interestingly, the designed composite exhibited an excellent catalytic performance for the epoxidation of α-pinene with air. Compared to isolated Co-MOF and ZSM-5, high yield of the product (94.4%) was obtained over the 0.5ZSM-5@Co-MOF-150 composite due to the highly dispersed Co-MOF nanosheet. This opens up interesting prospects for developing new zeolite@MOF composite catalysts as efficient heterogeneous catalysts.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
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IF 16.744
Jian Tian,Chuanhu Wang,Junwei Wu,Daohua Sun,Qingbiao Li
Pt works particularly well as a nanoparticle catalyst in the elimination of atmospheric pollutants, but its application is severely hampered by agglomeration and even poisoning in the presence of moisture. Hereby, a novel catalyst Pt@O-ZSM-5@OTS was synthesized to protect Pt, namely 0.5 wt% Pt was integrated into hollow ZSM-5 and subsequently coated hydrophobic octadecyltrichlorosilane (OTS) akin to the waterproof carapace. With the aid of various characterization techniques, the hybrid catalyst induced multiple marked features, such as dual-shell structure, hydrophobic microenvironment, and encapsulated active sites. Under excessively humid conditions (10 vol% H 2 O), the optimized Pt@O-ZSM-5@OTS2 exhibited a stable benzene conversion efficiency of 100 % for 120 h and outperformed the catalysts reported so far. Even reducing the reaction temperature to 170 °C, the conversion of benzene also reached 85 %, far exceeding the performance of untreated Pt@O-ZSM-5 (∼50 %). The outstanding stability stems from the hollow structure and OTS shell, which not only provide Pt with a protective shield against active site coverage, but also enhance competitive adsorption to benzene. Furthermore, DFT simulations unveil that the hydrophobic OTS shell enhances water resistance, consequently facilitates the oxidative degradation of contaminants at the active site. This work sheds light on novel strategies for the preservation of Pt by hydrophobic zeolite structures, as well as a deeper understanding of the elimination of aqueous VOCs.
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高影响因子
FUEL
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2022
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IF 8.035
Xiaopo Niu,Rong Zhao,Yunxi Han,Xiangwen Zhang,Qingfa Wang
Deep hydrogenation of polycyclic aromatic hydrocarbons is a feasible strategy to acquire high-performance aviation fuels, in which the key is to design highly active hydrogenation catalysts. Herein, hollow ZSM-5 (HZ) and silicalite-1 (HS) zeolites with hierarchical porous architectures were manufactured through a post-alkali treatment strategy, and further supported Pt to fabricate Pt/HZ-WI, Pt/HZ-SEA and Pt/HS-SEA catalysts employing wet impregnation (WI) and strong electrostatic adsorption (SEA) methods. The SEA catalysts presented higher metal dispersion, more election-deficient Pt δ+ species and stronger spillover hydrogen ability, thus resulting in better intrinsic hydrogenation properties in the deep hydrogenation reaction of phenanthrene than the WI ones. Moreover, Pt/HZ-SEA catalyst showed the supreme catalytic activity and the lowest activation energy of 52.11 kJ·mol −1 due to more hydrogenation active sites generated by the highly dispersed Pt clusters and the accelerated diffusion of reactants via the hierarchical porous architectures. Almost 100% selectivity to the deep hydrogenation products was achieved at rather low temperature of 220 °C. The Pt/HZ-SEA also displayed outstanding activity for hydrogenation of naphthalene, acenaphthylene and fluorene and excellent sulfur resistance. Furthermore, the acidic sites in HZ zeolite were favorable to boost the formation of electron-deficient Pt δ+ species having stronger deep hydrogenation ability and intensify the additional hydrogenation route through the spillover hydrogen. Finally, the DFT calculation results further verified that the Pt δ+ substances could heighten the adsorption of polyaromatics, thereby improving the deep hydrogenation activity.
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高影响因子
FUEL
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2022
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IF 8.035
Chenyao Bi,Zhuangzhuang Zhang,Daizong Han,Chengan Wang,Jianbo Zhang,Ming Sun,Qingqing Hao,Huiyong Chen,Xiaoxun Ma
Quality improvement of pyrolysis tar with yield increasing of high value-added components is highly desired for coal utilization. Herein, Ga-impregnated mesoporous ZSM-5 (Ga/MZ5) directed by organosilane surfactant of [3-(trimethoxysilyl) propyl] octadecyldimethylammonium chloride (TPOAC) is used as a catalyst for the catalytic upgrading of coal pyrolysis volatiles. Effective regulation by reduction and reduction/reoxidation promotes a secondary dispersion of gallium species from external surface deposition to micropore permeation. The comprehensive evaluation of catalytic upgrading performance indicates that the designedly regulated gallium species (mainly Ga + , GaH 2 + and GaO + ), feasible balance of Brønsted and Lewis active sites and mesopore diffusion superiority effectively contribute the yield increasing of both light-fraction ( M LF / M Tar ) and target products of BTEXN (benzene, toluene, ethylbenzene, xylene and naphthalene). The optimal catalyst of Ga/MZ5_R/O exhibited the highest value of M LF / M Tar (88 %) and highest yield of BTEXN (31.84 mg.g −1 ), which are 173 and 589 % higher than non-catalytic single pyrolysis and 133 and 280 % higher than those over the conventional Ga-impregnated ZSM-5 (Ga/Z5). Moreover, the possible reaction networks towards high value-added products of BTEXN based on the positive conversion of polycyclic aromatic hydrocarbons (PAHs), phenols, and other oxygen-containing compounds (abbreviated as PPO) is further proposed.
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高影响因子
ACS Omega
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2022
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IF 4.132
Huan Zhou,Wenwen Lin,Chao Chen,Chuang Liu,Jianghua Wu,Jianghao Wang,Jie Fu
As an essential chemical feedstock, aromatics can be obtained from biomass by catalytic fast pyrolysis (CFP) technology, in which diffusion limitation is still a problem. In this study, several ZSM-5 zeolites with intercrystal stacking macropores were synthesized by adding organosilanes (OSAs) with different alkyl chain groups. Due to the structure-directing effect of the OSA, the prepared ZSM-5 zeolites possess a larger external surface area and pore volume than Blank-Z5. Moreover, the pore size is related to the extent of anchoring of the OSA and silicon–aluminum species in the zeolite precursor. Pyridine Fourier transform infrared (Py-FTIR) and NH3-temperature-programmed desorption (TPD) analyses show that the obtained ZSM-5 zeolites have a higher Brønsted acidity and total number of acid sites. In addition, excessive addition of OSA is not conducive to the growth of ZSM-5 zeolites. The catalytic performance of the synthesized ZSM-5 zeolites was evaluated by Py-GC/MS. The larger external surface area and pore volume improve the accessibility of the acid sites and thus promote the conversion of biomass into aromatics.
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PubMed
高影响因子
CHEMOSPHERE
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2021
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IF 7.086
Jian Tian,Kok Bing Tan,Yichen Liao,Daohua Sun,Qingbiao Li
A zeolitic cage was introduced and rationally fabricated by encapsulating Pt nanoparticles (NPs) in hollow ZSM-5, a nanomaterial with a cavity and porous shell, for efficient catalytic oxidation of benzene. The structure and formation of the zeolitic cage were systematically investigated and characterized using transmission electron microscopy , nitrogen sorption investigations, X-ray photoelectron spectroscopy, nuclear magnetic resonance spectroscopy , and X-ray diffraction. The obtained hollow 0.2 Pt@ZSM-5 exhibited a comparable low-temperature catalytic activity with 0.5Pt/ZSM-5 with T 90 value of 178 °C. Various characterization techniques combined with adsorption experiments uncover the tremendous role of the zeolitic cage in the catalytic activity toward benzene oxidation. The porous shell prevented benzene dilution and the acidity originating from the hollow interior of ZSM-5 promoted the storage of benzene, thereby forming a high local concentration of benzene around Pt NPs, resulting in excellent catalytic performance. These findings provide valuable insights into the rational design of efficient catalysts for the catalytic oxidation of volatile organic compounds.
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PubMed
高影响因子
CHEMOSPHERE
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2021
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IF 7.086
Jinyu Hou,Daoxu Zhong,Wuxing Liu
Hazardous oil sludge (OS) poses a great challenge to the environment, whereas conventional treatment methods (i.e., incineration or pyrolysis-incineration) are relatively less value-added and will bring about air pollution problems. To realize the high-value utilization of OS, catalytic co-pyrolysis with waste biomass to produce platform chemicals was studied using TG-FTIR and Py (pyrolyzer)-GC/MS methods. Results showed that for the non-catalytic co-pyrolysis of RH (rice husk) and OS, the main synergy on weight loss was the greatly lowered initial pyrolysis temperature of RH (for ∼55 °C) at the lower temperatures and the reduced weight loss ratio of OS (∼10–18 wt%) within the higher temperature range. ZSM-5 catalyst promoted the degradation of OS and RH mixtures at < 150 °C, yet showed minor effects on their weight loss at higher temperatures. The oxygenated and aliphatic compounds from non-catalytic co-pyrolysis were efficiently converted, resulting in an increased relative yield of aromatics to the highest of 46% and an elevated selectivity to BTX (as high as 60%). Despite the relatively short carbon chain length of OS components, ZSM-5 was proved effective to activate the OS pyrolysis products, thus enhancing the further aromatization reactions with biomass pyrolysis intermediates. This study provides a novel method for value-added co-utilization of hazardous OS waste and abundant biomass waste, and thus is beneficial to producing renewable chemicals while reducing the environment pollutant.
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING SCIENCE
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2026
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IF 5.1
Shuang Liu,Lei Ye,Shaokai Huang,Peng Zhou,Mingxuan Ma,Miao Hu,Xujin Ren,Xin Pu,Xin Han,Jichang Liu
La/ZSM-5@ASA composites were developed by a stepwise assembly strategy. • La 3+ displaced the acidic protons and generated new BAS [Si-OLa(OH) 2 -Al]. • ASA overcoat passivated external surface acid sites and enabled pre-cracking. • Hierarchical La/ZSM-5@ASA shows high light-olefin selectivity in n -paraffin cracking. Catalytic cracking of surplus automotive fuels, heavy oil and waste plastics into light olefins is an efficient resource-reutilization strategy. Conventional ZSM-5 zeolites, however, suffer from limited light-olefin selectivity and coke-induced deactivation due to strong acidity and microporous constraints. Herein, a stepwise assembly strategy involving La modification and subsequent amorphous silica-alumina (ASA) overcoating was developed to construct core–shell catalysts with optimized acidity and diffusion. La modification modulated acid strength and distribution, and DFT calculations revealed it lowered the energy barrier of the rate-determining protonation step, promoting propylene formation. The ASA overcoat, applied via co-gelation, passivated external strong Brønsted acid sites and introduced open interfacial diffusion channels. This architecture enabled pre-cracking of reactants, promoting efficient C-C bond cleavage and suppressing secondary reactions. The optimized hierarchical La/ZSM-5@ASA(1:1) achieved 63.10% total ethylene and propylene selectivity in n -heptane cracking, outperforming ZSM-5 and 0.50La/ZSM-5 by 5.12% and 1.38%, respectively. This advantage is more pronounced for longer linear hydrocarbons, and the suppression of methane and coke precursors boosts atom utilization efficiency, indicating a carbon-economic cracking pathway.
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高影响因子
Journal of Environmental Chemical Engineering
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2023
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IF 7.7
Ruokun Jia,Jiayuan Deng,Xiaohang Yang,Ruisong Xue,Pengpeng Wang,Xingbo Bian,Qiyao Wang
Graphitic carbon nitride (CN) hold great promise as a photocatalyst for generating hydrogen energy via water splitting, owing to its remarkable ability to respond to visible light and its strong reduction capacity. However, the photocatalytic water splitting for H 2 evolution performance of pure CN was impeded by its low surface area, inadequate hydrophilicity, and unsatisfactory photoelectric conversion efficiency. Here we tackled these challenges by synthesizing a series of CN/H-ZSM-5 composites with varying amount of H-ZSM-5 zeolite using a straightforward thermal copolymerization method. The contact angle and N 2 adsorption-desorption measurements confirmed that the incorporated hydrophilic and porous H-ZSM-5 zeolite contribute to increased surface area and improved hydrophilicity of the CN/H-ZSM-5 composites. Meanwhile the resulting CN/H-ZSM-5 composites exhibited significant separation and migration enhancement of photoexcited charge carriers. Consequently, the optimized CN/H-ZSM-5 composite, containing 50 mg of H-ZSM-5 zeolite, demonstrated 13 times increase in photocatalytic H 2 production rate than that of pure CN. This work not only provided a competitively universal approach on the design of high-efficiency CN based photocatalyst, but also clarified the role of H-ZSM-5 zeolite in the H 2 evolution enhancement.
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高影响因子
ENERGY & FUELS
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2023
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IF 5.3
Haifeng Tian,Zhiyu Chen,Xing Yang,Peng Gao,Chunxue Jiao,Fei Zha,Yue Chang,Hongshan Chen
A method for the direct synthesis of hierarchical zeolites was developed by converting precursors of zeolites and mesoporous copolymers into homogeneous gels using conventional block copolymers as scaffolds. In this method, hydrothermal synthesis is accomplished on a steam-assisted basis, and the dry gel leaves the system free of the liquid water phase, which successfully avoids phase separation between the soft stencil and the solid silica phase. The catalytic performance of hierarchical zeolites was evaluated on a fixed-bed reactor for the methanol-to-aromatics reaction. The hierarchical structure greatly enhances the catalytic activity of the probe reaction due to the increased outer surface, decreased coke formation, and diffusion resistance in the microporous network. The selectivity of BTX reached 65.8%, and there was no significant deactivation after a reaction of 107 h. The transition state and energy barrier for methanol to aromatics were obtained by the minimum energy search of the LST/QST transition state.
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高影响因子
CHEMICAL ENGINEERING SCIENCE
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2021
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IF 4.311
Zenan Ni,Yuming Li,Yaoyuan Zhang,Yajun Wang,Guoqing Cui,Guiyuan Jiang,Zhen Zhao,Chunming Xu
Ga species with high dehydrogenation capability were prepared by H 2 -O 2 atmosphere treatment, and efficient balance of bifunctionality (dehydrogenation/cracking) was realized between Ga species and ZSM-5 over Ga/ZSM-5 based catalysts. Compared with parent Ga/ZSM-5, the conversion rate of n -butane was increased from 0.53 to 2.59 mmol·g −1 ·min −1 on Ga/ZSM-5 with H 2 -O 2 treatment. Kinetic analysis revealed that the apparent activation energy of n -butane catalytic cracking decreased largely from 141 to 47 kJ·mol −1 , which is attributed to the formation of new interaction between Ga species and ZSM-5 upon such an atmosphere treatment. It was also found Butane-O 2 treatment acted as a similar role with H 2 -O 2 treatment in enhancing the catalytic performance. On this basis, different Ga species were correlated with activity and kinetic data, and the effect of practical reaction atmosphere on Ga species was also investigated.
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高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2021
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IF 3.764
Gang Li,Shanhong Ma,Feng Ye,Liang Zhou,Yanhong Wang,Xuemei Lang,Shuanshi Fan
Effective water removal from bio-oil is very important for upgrading bio-oil quality via esterification because water strongly inhibits the conversion and simultaneously lowers the heating value. In the present study, ZSM-5 zeolite membranes are applied to make bio-oil pervaporation dehydration more efficient. An investigation of the permeation performance demonstrated that water mainly permeated through ZSM-5 membranes via intercrystalline pores, whereas intracrystalline pores in the membrane were almost completely blocked because of intensive membrane fouling. The above result showed that tuning water transport paths was significantly important when designing high-performance ZSM-5 membranes for bio-oil pervaporation. A decrease in membrane fabrication time successfully created loose membrane structures with abundant intercrystalline pores and resulted in highly selective and stable ZSM-5 membranes with significantly improved permeation flux in bio-oil dehydration. These robust ZSM-5 membranes show great potential for bio-oil refining in industrial applications.
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高影响因子
危险品化学品经营许可证（带存储）