NEW JOURNAL OF CHEMISTRY
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2024
·Vol. 48
·期 45
·19220-19228
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IF 2.7
Peng Lu,Qianwen Hu,Kui Wang,Shiyong Chen,Zongxiao Li,Xinjie Chen,Chuang Xing,Yanhong Wang,Ce Du
The efficient CO2 conversion to light olefins through hydrogenation is a feasible strategy to achieve carbon neutrality goals. Herein, a series of bimetallic Zn–Zr/supports are synthesized by a conventional impregnation method. We demonstrate that different supports endow catalysts with various specific surface areas, pore sizes, chemical adsorption performances, and acid densities. The effects of different support-loaded Zn–Zr coupled with SAPO-34 on CO2 hydrogenation to light olefins are investigated systematically. The CO2 conversion of Zn–Zr/Q10-SAPO-34, Zn–Zr/Q50-SAPO-34, Zn–Zr/γAl2O3-SAPO-34, Zn–Zr/MgO-SAPO-34 and Zn–Zr/S-1-SAPO-34 is 11.4%, 9.2%, 24.0%, 8.8%, and 16.2%, respectively, with corresponding light olefin selectivity of 39.0%, 28.1%, 30.4%, 4.8%, and 14.7%, respectively. Significantly, γAl2O3 is more conducive to CO2 conversion, while Q10 tends to produce light olefins. This work provides an effective reference for support selection in CO2 hydrogenation to light olefins.
研究领域:
化学工程
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环境科学
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DOI
高影响因子
JOURNAL OF CATALYSIS
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2024
·
IF 6.5
Peng Zhang,Fangfang Li,Xuefang Yao,Pengze Zhang,Yukai Wu,Mengmeng Xi,Fanhui Meng,Lihua Kang,Mingyuan Zhu
The GaZrO x solid solution has been recently employed in OX-ZEO bifunctional catalysts for efficient conversion of syngas to light olefins, but it remains challenging to identify the specific contributions of Zr and Ga and to understand the detailed reaction mechanisms due to the structural complexity. To address this complexity and elucidate the active sites over the Zr-Ga oxide system, this study presents a catalyst designed by physical mixing ZrO 2 with different crystalline phases ( m -ZrO 2 & t -ZrO 2 ) and α -Ga 2 O 3 . The physical mixture of m -ZrO 2 and α -Ga 2 O 3 achieves a high CO conversion of 39.1 %, with light olefins selectivity of 87.3% among hydrocarbons after combined with SAPO-34, surpassing the performance of physical mixture of t -ZrO 2 and/or α -Ga 2 O 3 with SAPO-34. Combining the various characterizations and DFT calculations, we have confirmed that m -ZrO 2 site, enriched with oxygen vacancies and surface hydroxyl groups, is essential for CO adsorption and HCOO* intermediate formation, while the α -Ga 2 O 3 site plays a key role in the dissociation of H 2 . Furthermore, the electron transfer from m -ZrO 2 to α -Ga 2 O 3 in their mixture is more efficient than in a physically mixed t -ZrO 2 and α -Ga 2 O 3 . This accelerates the H 2 dissociation and boosts the spillover of hydrogen from α -Ga 2 O 3 to m -ZrO 2 , leading to the formation of more CH 3 O* intermediates and higher light olefins yield when combined with SAPO-34.
研究领域:
催化化学
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材料科学
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计算化学
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产品关联
DOI
高影响因子
Clean Energy
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2025
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IF 3.7
Jiang Zhenhua,Xia Wei,Zhang Yanli,Wang Xinrui,Dong Mingyuan,Chen Kun,Liu Dong,Lu Baowang
This study aims to compare the catalytic performance of ZSM-5 and SAPO-34 zeolite catalysts in the conversion of ethanol. Through experiments conducted at different temperatures (773 K and 673 K), it was found that SAPO-34 initially exhibits superior propylene selectivity compared to ZSM-5. However, the propylene yield on SAPO-34 gradually decreases, while the ethylene yield increases with time on stream. density functional theory calculations were employed for the investigation of reaction mechanism. The results indicate that the SAPO-34 catalyst surface favors propylene desorption, which beneficial for its initial high propylene selectivity. Nevertheless, the smaller pore structure of SAPO-34 limits the effective diffusion of products, leading to product accumulation within the pores and potentially causing catalyst coking and deactivation. By combining the experimental results with theoretical calculation, this study not only explored the selectivity difference between SAPO-34 and H-ZSM-5 in ethanol conversion reaction, but also revealed the influence of different molecular sieve catalyst structures on product distribution and catalyst stability.
研究领域:
催化化学
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材料科学
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计算化学
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产品关联
DOI
高影响因子
Journal of Inorganic and Organometallic Polymers and Materials
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2024
·
IF 3.9
Liu Hao,Wang Yanlin,Yuan Hong,Luo Wenbo
Nanoscale ZSM-5 zeolites (NZSM-5) having different crystal sizes and Si/tetrapropylammonium hydroxide (TPAOH) molar ratios were synthesized using a hydrothermal method. These materials were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and N 2 adsorption–desorption. The results showed that each zeolite was highly crystalline regardless of the Si/TPAOH ratio and that the Brunauer–Emmett–Teller surface areas were in the range of 329−392 m 2 /g. The random aggregation of these nanoparticles resulted in the formation of numerous intergranular mesopores. These NZSM-5 zeolites were applied to the catalytic cracking of oleic acid to prepare light olefins and light aromatics using a laboratory-scale fixed bed reactor. The zeolite having a Si/TPAOH ratio of 10/5 showed the best catalytic activity and provided light olefins yield of 55% and selectivity of BTX in liquid phase products of 18%, respectively, at 500 °C. The small crystal size and abundant intergranular mesopores in this specimen resulted in shorter diffusion paths and an increase in the external specific surface area that both inhibited coke deposition and ensured accessible acid sites. Graphical Abstract
研究领域:
化学工程
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材料科学
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DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
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2024
·
IF 4.8
Mengkun Luan,Xiangjie Lei,Yu Fan
To increase the yield of light olefins during the catalytic pyrolysis of alkanes, a novel hierarchical Fe-incorporated ZSM-5 molecular sieve (FeM-Z5) was synthesized using an Fe-based metal-organic framework (Fe-MOF) as a mesoporogen and iron source through the dry gel conversion (DGC) method. In contrast to the conventional method of incorporating Fe species into ZSM-5 via impregnation, the DGC method incorporates Fe species into the framework of ZSM-5, decreasing the amount of Brønsted (B) acid sites and thereby inhibiting the side reactions of hydrogen transfer during the catalytic pyrolysis of alkanes. Compared with the FeN-Z5 catalyst prepared by the DGC method with Fe(NO 3 ) 3 as an iron source, FeM-Z5 had a larger amount of strong B acid sites and more mesopores with a size range of 10–40 nm originating from the decomposition of Fe-MOF; these aspects improved n-pentane pyrolysis and ethylene and propylene diffusion. As a result, the optimal FeM-Z5 catalyst exhibited the highest yield of ethylene and propylene (33.4 wt%) and the lowest deactivation rate (0.07 %/h) among the prepared catalysts during the catalytic pyrolysis of n-pentane.
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
Sustainable Energy & Fuels
·
2024
·Vol. 9
·期 1
·152-171
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IF 5
Haoyu Liu,Wenbo Luo,Ke Wang,Yanlin Wang,Hong Yuan
The bolaform surfactant C6H13-N+(CH3)2-C6H12-N+(CH3)2-C6H12-O-C6H4-C6H4-O-C6H12-N+(CH3)2-C6H12-N+(CH3)2-C6H13 (BCPH-6-6-6) was synthesized and used to guide the synthesis of hierarchical ZSM-5 nanosheets (HZN) for use as zeolite catalysts. The number of acidic sites and the Al distribution in the zeolite pores were varied by changing the amounts of sodium sulfate and Al in the initial gel. The X-ray diffraction, Fourier transform infrared spectroscopy, scanning electronic microscopy, NH3 temperature programmed desorption, 27Al magic angle spinning nuclear magnetic resonance spectroscopy and N2 adsorption/desorption were used to characterize these materials. These zeolites each had a well-developed hierarchical system and specific surface areas as high as 631 m2 g−1, indicating that the BCPH-6-6-6 formed lamellar micelles based on π–π stacking. Interconnected hierarchical pore structures were retained after the templating agent was removed. The HZN sample exhibited a 90° rotational intergrowth structure and retained a large number of lamellae. The same material had a high concentration of acidic sites and contained Al in a tetrahedral coordination framework. The catalytic cracking of oleic acid using this zeolite gave light olefin yields up to 52.2% at 500 °C, exceeding the performance of conventional ZSM-5 (38.9%), and the catalyst remained active for up to 60 h. At 450 °C, the BTX selectivity of 6.72% obtained with this material also exceeded that from the conventional ZSM-5. These results were attributed to the connected hierarchical pores of the HZN, which promoted diffusion and provided higher carbon resistance.
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
CHEMICAL ENGINEERING JOURNAL
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2024
·
IF 13.3
Fan Xu,Xin Meng,Rui Zhao,Daoming Jin,Wenhua Dai,Dandan Yang,Zhong Xin
The utilization of CO 2 for the production of light olefins through catalysis with iron-based catalysts presents a viable strategy to address the challenges of carbon neutrality. In this study, we synthesized a novel hybrid catalyst Fe 2 O 3 @ZrO 2 , derived from the pyrolysis of dual metal–organic frameworks (NH 2 -MIL-88B@UiO-66). Under specific conditions (340 °C, 3.0 MPa, CO 2 /H 2 = 1:3, 10000 mL g cat −1 h −1 ), the Fe 2 O 3 @ZrO 2 catalyst exhibited a notable space–time yield of light olefins at 12.7 mmol g −1 h −1 . The characterizations results show an electron transfer from ZrO 2 to the Fe 2 O 3 surface was observed at the heterointerface of Fe 2 O 3 and ZrO 2 . This electron transfer mechanism was identified as advantageous for the formation of the active phase Fe 5 C 2 . This research introduces an innovative use of the hybrid Fe 2 O 3 @ZrO 2 catalyst derived from MOF-on-MOF, holding significant promise in advancing the field of CO 2 hydrogenation catalysts.
研究领域:
催化化学
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材料科学
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环境科学
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DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2022
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IF 4.326
Yuen Bai,Dongyang Liu,Liang Zhao,Jinsen Gao,Chunming Xu,Haitao Pang,Xuhui Gao
The influences of different B (Brønsted) acid site concentrations and the ratio of L (Lewis)/B (Brønsted) on the cracking pathways and product distributions in hexane cracking reactions as a model component of naphtha were investigated. The sodium-modified ZSM-5 catalysts were prepared by the wet impregnation method, and the Si–OH–Al groups of ZSM-5 were broken in the post-treatment process, resulting in a decrease in the number of strong B acid sites (SBAS) and an increase in the number of strong L acid sites (SLAS). The correlations between the n-hexane catalytic cracking reaction pathways and the catalyst acid properties were established. The reduced SBAS inhibits secondary reactions of light olefins such as hydrogen transfer, oligomerization, cyclization, and aromatization, while the increased SLAS and the ratio of SLAS/SBAS promoted the β scission reactions that significantly improved the yields of light olefins. Consequently, the appropriate SBAS and SLAS/SBAS ratios are desirable for the production of ethylene and propylene. The optimal SBAS concentration and SLAS/SBAS ratio ranged from 4.44 to 6.69 μmol/g and 9.18–11.86 for maximum ethylene and propylene yields of 16.14% and 14.63% in hexane catalytic pyrolysis reactions, respectively. Furthermore, the optimally prepared catalysts illustrated superior reactivities and catalytic stabilities in naphtha catalytic pyrolysis reactions under industrial conditions.
研究领域:
化学工程
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催化材料
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DOI
高影响因子
Catalysts
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2022
·Vol. 12
·期 11
·1457
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IF 4.501
Xiaoqiao Zhang,Jianhong Gong,Xiaoli Wei,Lingtao Liu
In this study, a sequential reaction using selected metal oxides, followed by ZSM-5-based catalysts, was employed to demonstrate a promising route for enhancing light olefin production in the catalytic cracking of naphtha. The rationale for the reaction is based on the induction of alkenes into hydrocarbon feeds prior to cracking. The optimum olefin induction was achieved by carefully optimizing the dehydrogenation active sites Mo/Al2O3catalyst. The formed alkenes have a lower activation energy for C-H/C-C bond breaking compared to alkanes. This could accelerate the formation of carbenium ions, thus promoting the conversion of n-octane to produce light olefins. Detailed product distribution and DFT calculation indicated a remarkable increase in ethylene and propylene production in the final product through a modified reaction pathway. Compared with the common metal-promoted zeolite catalysts, the new route could avoid the block of zeolite channels and corresponding decreased catalytic cracking activity. The feasibility of the proposed route was confirmed with different ratios of dehydrogenation catalyst to the reactant. The highest yields of ethylene and propylene reached 13.22% and 33.12% with ratios of Mo/Al2O3and ZSM-5-based catalyst ton-octane both 10:1 at 600 °C. Stability tests showed that the catalytic activity of the double-bed system was stable over 10 cycles.Keywords:naphtha;dehydrogenation;cracking;DFT calculation;synergetic effect
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
SOLID STATE SCIENCES
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2025
·
IF 3.3
Yanlin Wang,Hao Liu,Haoyu Liu,Hong Yuan
A series of nanosized ZSM-5 (SNZSM-5) zeolites has been synthesized by the seed-assisted method using silicalite-1 as seeds. Catalytic cracking of oleic acid to produce light olefins and light aromatics using SNZSM-5 as the catalyst was performed using a laboratory-scale fixed-bed reactor. The effects of the crystallization time and Si/Al molar ratio on the morphology and multilamellar structure of SNZSM-5 were studied to reveal how these properties affect the catalytic performance. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction, temperature-programmed desorption of ammonia, and N 2 physisorption and desorption were performed to characterize the morphological features, acidities, and pore structures of the SNZSM-5 nanozeolites. Compared with conventional ZSM-5 zeolite, the SNZSM-5 nanozeolites possessed smaller particle diameters (90–450 nm), and they thus contained more intercrystalline voids. The Brunauer–Emmett–Teller surface areas (211–309 m 2 g −1 ) and mesopore volumes (0.08–0.27 cm 3 g −1 ) were both higher than those of ZSM-5 zeolite. Moreover, owing to the larger specific surface areas of the nanocrystals, more acidic sites can be exposed. Therefore, the SNZSM-5 nanozeolites showed higher catalytic activity and stability than conventional ZSM-5. The catalytic activity could be sustained for up to 35 h. Under the conditions of a reaction temperature of 500 °C, an oleic acid flow rate of 0.04 mL min −1 , and a nitrogen flow rate of 30 mL min −1 , the SNZSM-5 nanozeolite prepared with a Si/Al molar ratio of 16 showed the highest catalytic activity, producing up to 67 % yield of light olefins and showing 14.5 % selectivity for light aromatics.
研究领域:
化学工程
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催化材料科学
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产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2021
·Vol. 11
·期 7
·2577-2588
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IF 6.119
Xian Wu,Weixin Qian,Haitao Zhang,Zhonghao Han,Hewei Zhang,Hongfang Ma,Dianhua Liu,Qiwen Sun,Weiyong Ying
CeO2 nanorods with a mean width of 11.9 nm were synthesized via a facile hydrothermal method. Subsequently, Fe/CeO2 and Fe/CeO2@xMnO2 catalysts were prepared from the CeO2 nanorods and applied in the high-temperature Fischer–Tropsch synthesis of light olefins. Results show that the CeO2 support donates electrons to Fe species, which promotes the dissociation of CO while suppressing the hydrogenation reaction, and then improves the selectivity to light olefins. The synergistic effect between Mn and Ce can improve the oxygen mobility on the catalyst surface and promote the electron-donating ability of Ce, thereby promoting the formation of χ-Fe5C2 and further improving the selectivity to light olefins. However, excess Mn hinders the contact between CeO2 and Fe species and the migration of O atoms, and electron transfer from Ce to Fe can be blocked. Additionally, the reduction of iron oxides was suppressed and subsequently the CO conversion was reduced. The best hydrocarbon distribution for light olefins was 40.4% at a CO conversion of 39.9% over the Fe/CeO2@0.2MnO2 catalyst.
研究领域:
化学工程
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材料科学
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催化反应
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产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
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2022
·
IF 3.656
Jiale Zhu,Siyan Yan,Guohao Xu,Xuedong Zhu,Fan Yang
A variety of HZSM-5 zeolites with different b-axis thicknesses and SiO 2 /Al 2 O 3 were fabricated by simply modifying urea content and Al source feeding in the initial gel, respectively. Multiple characterization technologies including XRD , SEM, N 2 adsorption-desorption, NH 3 -TPD and Py-IR were employed to investigate physicochemical properties of these samples and the possible crystallization mechanism was proposed that adsorption of urea molecules on (010) facet was the key factor for fabricating thin-sheet HZSM-5 zeolites. The results of hexane cracking reaction revealed that the selectivities of light olefins reached 46.5% when controlling b-axis thickness to 340 nm, exceeding the control sample by 12.2%. Furthermore, the effect of SiO 2 /Al 2 O 3 under this b-axis thickness was also investigated and concluded that keeping SiO 2 /Al 2 O 3 to 200 could exhibit the optimum catalytic performance with the conversion of 95.5% and light olefins selectivities of 56.7%. The reaction conditions were optimized to be 600 °C at the N 2 flow rate of 25 mL/min and WHSV of 3 h −1 to arouse the best performance. Under this condition, the distribution of ethene and propene was quite close to that of thermodynamic equilibrium. Based on these results, the primary and secondary products were uncovered, and further the reaction pathway of hexane cracking was disclosed. This new strategy to synthesize sheet-like catalysts for enhancing the catalytic properties in hexane cracking also laid a solid foundation for the study of the catalysts on light oil cracking in industry.
研究领域:
化学工程
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催化材料科学
✓ 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）