FUEL
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2024
·
IF 6.7
Mei Ren,Jun Li,Manhong Huang,Donghui Chen,Xuelian Chen,Qi An,Songmei Sun
The escalating environmental issues resulting from waste plastic necessitate innovative decomposition methods that optimize conversion rates and product selectivity. In this study, we demonstrate that linear low-density polyethylene (LLDPE) can be effectively hydrothermolyzed into C1 − C4 compounds with a selectivity of 100 % in the presence of trace water on H-ZSM-5 catalyst under a relatively low temperature of 220 °C. Water plays a dual role here as both a solvent and a reactant. It was found the density of Brønsted acid sites is crucial for LLDPE decomposition, serving as the primary active centers for cracking LLDPE chains. In-situ EPR studies indicate a synergistic mechanism of free radical and carbenium ion pathways in LLDPE depolymerization. Density Functional Theory (DFT) simulations show that the depolymerization starts with the cleavage of a C–C bond in polyethylene, instigated by a hydrogen radical from the Brønsted acid site, leading to various intermediate stages for the formation of tert -butanol, acetone and acetic acid from two potential pathways. The presence of water is crucial in these pathways, aiding bond breakages and the creation of oxygenated products in the Brønsted acid site. This study represents a substantial leap forward in sustainable methodologies for upcycling plastic waste.
研究领域:
环境科学
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催化化学
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材料科学
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产品关联
DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2017
·Vol. 11
·期 4
·564-574
·
IF 1.712
Song Baodong,Li Yongqiang,Cao Gang,Sun Zhenhai,Han Xu
In the transformation of methanol to gasoline (MTG), the selectivity to gasoline and the aromatic content in the produced gasoline are important factors. The catalytic activities of steam-treated and non-steam-treated nano-scale H-ZSM-5 (NHZ5) catalysts impregnated with Ag(I), Zn(II) or P(V) have been investigated in a continuous flow fixed bed reactor. The NH 3 -TPD results showed that after impregnation, the Ag/NHZ5, Zn/NHZ5 and P/NHZ5 catalysts contained comparatively more strong, medium-strong and weak acid sites, respectively. Treatment with steam decreased the number of acid sites in all the catalysts, but the pore volumes in the catalysts were larger which improved carbon deposition resistance resulting in prolonged lifetimes. After 6 h of MTG reaction, the selectivity to gasoline for the steam-treated catalysts,
\(Ag_{H_2 O} /NHZ5\) , \(Zn_{H_2 O} /NHZ5\) and \(P_{H_2 O} /NHZ5\) were 70.5, 68.4 and 68.7 wt-%, respectively, whereas their respective aromatic contents in the produced gasoline were 61.9, 55.4 and 39.0 wt-%. Thus \(P_{H_2 O} /NHZ5\) is the most promising catalyst for MTG applications which can meet the China IV gasoline standard that the amount of aromatics in gasoline should be less than 48 wt-%.
研究领域:
催化化学
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能源化工
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材料科学
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表面科学
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石油炼制
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DOI
高影响因子
Molecular Catalysis
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2025
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IF 4.9
Shengxin An,Shuaibo Zhao,Jingting Jin,Tao He,Yuhao Wang,Na Kong,Jie Zhou,Wenzhi Li
Great expectations have been placed on bimetallic co-modified zeolite for the direct oxidation of methane to methanol. In this work, H-ZSM-5 zeolite was modified with bimetallic copper and zinc via ion-exchange method. Numerous experiments were conducted and the methanol yield of 44,302.70 μmol·g cat −1 ·h −1 was obtained over 1Cu/2Zn-ZSM-5 catalyst. A series of characterization analyses confirmed that the introduction of Zn increased the proportion of active Cu species bound to extra-framework oxygen by altering the electronic state of copper. The bis (μ-oxo) dicopper ligand was identified as the active site for methane oxidation. The possible reasonable reaction pathway was the free radical reaction. This work provides a valuable guidance for the preparation of co-modified zeolite catalysts for the direct oxidation of methane to methanol.
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
CATALYSIS COMMUNICATIONS
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2024
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IF 3.4
Chenan Yang,Yi Liu,Ying Hu,Peng Wang,Yuling Yang,Shangxing Chen,Zongde Wang,Xiang Li
Catalytic valorization of biomass into high energy density fuels plays a vital role in order to achieve future carbon neutrality. Herein, a class of H-MZ-5 catalysts with different mesoporous pore structures and acid site properties were synthesized. Among them, HMZ-5 prepared with tetrapropylammonium bromide (TPABr) and hexadecyltrimethylammonium bromide (CTAB) as templating agents showed the most excellent catalytic activity and selectivity of α-pinene dimerization. Under optimal catalytic conditions, 100% α-pinene was converted with 89.6% selectivity to dimers. The efficient catalytic activity and affordability of the catalysts in this system make it promising for industrial applications.
研究领域:
化学工程
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能源科学
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催化材料
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产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
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2021
·
IF 5.467
Xinyu Li,Shunyu Han,Dongdong Guan,Nanzhe Jiang,Jingzhe Xu,Sang-Eon Park
The direct synthesis of H-ZSM-5 catalysts from natural aluminosilicate clays is important for the conversion of raw clay resources to high-value-added products. Herein, the solid-like-state conversion was used to directly prepare nano-H-ZSM-5 with uniform morphology and particle size (~300 nm) from leached illite (ISR) as both Si and Al source. Crystallization kinetics indicated that the reactivity of ISR is similar to that of commercially fabricated products and ISR could be rapidly (within 5 h) converted into nano-H-ZSM-5, the crystallinity , morphology, and crystal size of which were strongly affected by the amount of tetrapropylammonium hydroxide (TPAOH). Additionally, the residual Al of ISR uniformly intruded the H-ZSM-5 framework to provide active sites for the methanol-to-aromatics reaction. The catalytic performance stability and BTX selectivity of nano-H-ZSM-5 for this reaction surpassed those of a commercial ZSM-5 catalyst because of the synergistic effect among the specific surface area and volume of micropores , uniform morphology and particle size, and homogeneously distributed acidic sites. This rapid, efficient, and cleaner synthesis reported herein was shown to have no necessity of ion exchange with ammonium salts, to be H-form of ZSM-5 as well as improve the productivity of HZSM-5 catalysts. And consequently, it is expected to reduce the cost of synthesis and provide an opportunity for the comprehensive development and utilization of illite clay resources.
研究领域:
材料科学
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催化化学
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产品关联
DOI
高影响因子
RENEWABLE ENERGY
·
2021
·
IF 8.001
Feng Lin,Yulong Ma,Yonggang Sun,Kanghe Zhao,Tingting Gao,Yingbo Zhu
Due to the inertness and structural complexity of lignin, upgrading lignin to biofuels and fine chemicals still faces great challenges. In this paper, a one-pot method was used to catalyze straw lignin with H-ZSM-5 supported by Ni and Ru bimetals, and the lignin conversion rate reached 88.1%. The yield of monophenol was 19.5%, of which the yield of 4-ethylphenol and 4-ethylguaiacol was 4.9% and 3.8%, respectively. The 2D HSQC NMR analysis confirmed that the Ni–Ru/H-ZSM-5 catalyst had an obvious activity of breaking C β -O bonds before and after the reaction. The result showed that after loading metal Ni and Ru, the Lewis acid of the catalytic system was greatly increased, which caused electron transfer between Ni and Ru. 3Ni-1.5Ru/H-ZSM-5 had the strongest activity due to the largest synergy among Ni, Ru and H-ZSM-5. The synergy was the key factor leading to the cleavage of C–C and C–O bonds in straw lignin and the high-performance catalytic degradation of lignin. Besides, the effect of reaction solvent and hydrogen resource on upgrading lignin to fine chemicals over 3Ni-1.5Ru/HZSM-5 catalyst was also intensively investigated. This research developed a method for the direct conversion of lignin into valuable monophenols.
研究领域:
催化化学
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生物质转化
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产品关联
DOI
高影响因子
JOURNAL OF RARE EARTHS
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2022
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IF 4.632
Feng Lin,Yudan Zhong,Yulong Ma,Yonggang Sun,Xiuqin Men,Yingbo Zhu
Hydrodeoxygenation (HDO) of renewable lignin-derived biomass in aqueous-phase to produce high value-added products is of great significance. However, developing new catalysts with high activity and excellent stability in an aqueous phase faces considerable challenges. Rare earth doping can effectively regulate the water exchange rate constant (WERC) value of the catalyst and play an important role in promoting the hydrolysis of ether bonds. Therefore, in this paper the bimetallic supported catalyst Ni–La 2 O 3 /H-ZSM-5 doped with rare earth metal La 2 O 3 was prepared, and used to catalyze the conversion of the lignin model compound guaiacol to cyclohexanol in the aqueous phase. The conversion of guaiacol catalyzed by 10Ni–3La 2 O 3 /H-ZSM-5 reaches 100%, and the selectivity of the product cyclohexanol is 85%. A series of characterizations illustrate that the doping of La 2 O 3 causes the electron transfer between La 2 O 3 –Ni and changes the distribution of Ni, and a strong metal carrier interaction occurs between the bimetallic Ni–La 2 O 3 and H-ZSM-5. This can effectively promote the hydrolysis of the C–O ether bond in guaiacol and significantly improve the activity of the catalyst. The possible catalytic reaction mechanism of Ni–La 2 O 3 /H-ZSM-5 catalytic conversion of guaiacol was proposed.
研究领域:
催化化学
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生物质转化
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
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2022
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IF 6.137
Weiquan Li,Die Hu,Ke Yin,Chenglong Yu,Bichun Huang
A series of hierarchical Ru-Ce/H-ZSM-5 were designed and synthesized using the sol-gel method, and they were applied as catalysts for the catalytic combustion of chlorobenzene. The pore diameter of the catalyst was adjusted using an amount of sodium alginate (SA). Among all of the catalysts synthesized, the 0.8 wt.%Ru-10 wt.%Ce/H-ZSM-5 catalyst with a crystallization recipe of 1SiO 2 : 0.02Al 2 O 3 : 0.15TPAOH: 0.04SA: 40H 2 O (named RCZA-0.04) exhibited the optimal catalytic activity, with the 90% conversion of chlorobenzene at 247 °C. In addition, the RCZA-0.04 catalyst maintained superb stability during a long-term reaction at 325 °C. The results of characterizations demonstrated that RCZA-0.04 possessed the largest mesoporous volume, which reduced the diffusion resistance of chlorobenzene and increased the dispersion of the active components, thereby enhancing the catalytic activities. Moreover, the RCZA-0.04 catalyst possessed a low Brønsted/Lewis ratio, which was conducive to the adsorption of chlorobenzene and the cleavage of the C Cl bond.
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
BMC Chemistry
·
2019
·Vol. 13
·期 1
·1-15
·
IF 0
Guo J.,Ma Yu L.,Yu Jia Y.,Gao Yu J.,Ma Ning X.,Wu Xiao Y.
Herein, 2-(2-methoxyphenoxy)-1-phenylethanol (β- O -4), 2-methoxyphenyl anisole (α- O -4) and 4-phenoxyphenol (4- O -5) were selected as typical lignin model compounds. Given the effectiveness of traditional acid–base catalysts for lignin depolymerisation, a novel Ni/CaO–H-ZSM-5(60) catalyst was prepared to investigate the difficulty level of C–O bond of three model compounds cleavage in ethanol. It was observed that Ni/CaO–H-ZSM-5(60) had prominent performance on the C–O bond cleavage at very mild conditions (140 °C, 1 MPa H 2 ). Among them, the C–O bond of α- O -4 and β- O -4 could be completely cleaved within 60 min. Although the C–O bond of 4- O -5 had high bond energy, 41.2% of conversion was occurred in 60 min. The introduction of CaO could regulate the acidity of H-ZSM-5 to enhance the ability to break C–O bonds. Moreover, the possible pathways of C–O ether bonds in three lignin model compounds cleavage were proposed in order to selectively obtain target products from the raw lignin degradation.
研究领域:
化学工程
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催化科学
✓ 已验证
DOI
Journal of Central South University
·
2020
·Vol. 26
·期 11
·2974-2986
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IF 1.249
Xu Si-quan,Pan Dong-hui,Xiao Guo-min
With the aim of achieving a high 5-hydroxymethylfurfural (HMF) yield from glucose with H-ZSM-5 catalyst at low cost, three inexpensive biphasic reaction systems, H 2 O—tetrahydrofuran (THF), H 2 O—2-methyltetrahydrofuran (MeTHF) and H 2 O’2-butanol, were discovered and proved to be particularly effective in promoting the formation of HMF from glucose over H-ZSM-5 zeolite. In order to determine the optimal process conditions, the effects of various experimental variables, such as reaction temperature, reaction time, catalyst dosage, volume of organic solvent, as well as inorganic salt type on glucose conversion to HMF in three systems were investigated in detail. It was found that under optimal reaction conditions, H 2 O—THF, H 2 O—2-butanol and H 2 O—MeTHF allowed the glucose dehydration process to achieve HMF yields of up to 61%, 59%, and 50%, respectively. Moreover, in the three biphasic systems, the H-ZSM-5 catalyst was also demonstrated to maintain excellent stability. Thus, the catalytic approach proposed in this paper can be believed to have potential prospects for industrially efficient and low-cost production of HMF.
研究领域:
化学工程
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生物质转化
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2025
·Vol. 15
·期 9
·826
·
IF 4
Anran Zhu,Zhufan Zou,Yu Cong,Yinghua Yin,Ning Li
A novel two-step strategy was developed for the efficient synthesis of decalin and octahydroindene from lignocellulose-derived platform compounds. In the first step, bicyclic intermediates were directly generated via a cascade dehydration/Robinson annulation of 4-hydroxy-2-butanone with cyclohexanone (or cyclopentanone). Among the evaluated catalysts, CaO demonstrated the highest activity and selectivity. Based on CO2-TPD results, the excellent performance of CaO can be rationalized by its proper basicity. In the second step, these intermediates were selectively hydrodeoxygenated to decalin (or octahydroindene) over Ni/H-ZSM-5 catalyst. Under the investigated reaction conditions, ~90% overall yields of decalin and octahydroindene were achieved. This work provides a viable strategy for the selective conversion of lignocellulose-derived platform compounds to the additives for improving the thermal stability of aviation fuel.
研究领域:
催化化学
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可再生能源
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绿色化学
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生物质转化
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燃料添加剂合成
✓ 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）