CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2021
·
IF 3.171
Shuo Li,Jianlin Cao,Xiang Feng,Yupeng Du,De Chen,Chaohe Yang,Wenhua Wang,Wanzhong Ren
Elucidating the confinement effect harbours tremendous significance for isobutane alkylation with C 4 olefin . Herein, the confinement effect over zeolite catalysts was elucidated by combining DFT calculations, experiments (using the novel Beta zeolite exposing only external surfaces (Beta-E) and conventional Beta-I zeolite with both external and internal surfaces) and multi-techniques ( e . g ., TGA-DTG, HRTEM, SEM and XRD). It is found that the main active sites for C 4 alkylation reaction are located on internal surface rather than external surface. On the external surface, the hydride transfer reaction does not occur because the H-shared intermediate cannot be formed without the confinement effect. Moreover, the external surface has stronger selectivity for C 4 olefin adsorption than isobutane, leading to enhanced oligomerization reactions. Therefore, the suitable micropore with confinement effect is essential for zeolite-catalyzed C 4 alkylation. The atomic-scale insights of this work are of great referential importance to the design of highly effective zeolite catalyst.
研究领域:
催化化学
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材料科学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
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2022
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IF 12.92
Zhaopeng Liu,Youming Ni,Zhongpan Hu,Yi Fu,Xudong Fang,Qike Jiang,Zhiyang Chen,Wenliang Zhu,Zhongmin Liu
The utilization of metal oxide-zeolite catalysts in the syngas-to-olefin reaction is a promising strategy for producing C 2 –C 4 olefins from non-petroleum resources. However, the effect of the crystal phase of metal oxides on the catalytic activity of these oxides is still ambiguous. Herein, typical metal oxides (ZnO/ZrO 2 ) with different crystal phases (monoclinic ( m -ZrO 2 ) and tetragonal ( t -ZrO 2 )) were employed for syngas conversion. The (ZnO/ m -ZrO 2 +SAPO-34) composite catalyst exhibited 80.5% selectivity for C 2 –C 4 olefins at a CO conversion of 27.9%, where the results are superior to those (CO conversion of 16.4% and C 2 –C 4 olefin selectivity of 76.1%) obtained over (ZnO/ t -ZrO 2 +SAPO-34). The distinct differences are ascribed to the larger number of hydroxyl groups, Lewis acid sites, and oxygen defects in ZnO/ m -ZrO 2 compared to ZnO/ t -ZrO 2 . These features result in the formation of more formate and methoxy intermediate species on the ZnO/ m -ZrO 2 oxides during syngas conversion, followed by the formation of more light olefins over SAPO-34. The present findings provide useful information for the design of highly efficient ZrO 2 -based catalysts for syngas conversion.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2024
·Vol. 53
·期 6
·2526-2533
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IF 3.5
Jia-Min Lyu,Shen Yu,Zhan Liu,He-You Du,Ming-Hui Sun,Chun-Mu Guo,Yi-Long Wang,Yu Li,Li-Hua Chen,Bao-Lian Su
Excessive emission of CO2 into the atmosphere has severely impacted the global ecological environment. Converting CO2 into valuable chemicals and fuels is of great significance for sustainable development. However, low activity and undesirable selectivity often result from the inherent inertness of CO2. Herein, K- or/and Zn-modified Fe-based catalysts were prepared by an incipient-wetness impregnation method for CO2 hydrogenation via a cascade reaction. The results indicate that K species exist as K2O while Zn species exist as ZnFe2O4. In the CO2 hydrogenation pathway, K2O facilitates the adsorption of CO2 and restrains the adsorption of H2, accelerating the transformation of CO2 into C2–C4 olefins rather than paraffins while Zn species promote the dispersion of Fe species, leading to improved activity. Synergistically, a K- and Zn-modified Fe-based catalyst (2Zn–10K–Fe/Al) shows excellent catalytic CO2 hydrogenation activity, achieving a CO2 conversion of 77% which is 1.8 times that (42%) of the unmodified Fe-based catalyst (Fe/Al). Our catalyst also shows a significantly promoted selectivity to C2–C4 olefins of 17% in comparison with the Fe/Al catalyst (0%). It is envisioned that such a binary effect of elements might contribute to the low-cost and industrial production of Fe-based catalysts for selective CO2 conversion.
研究领域:
催化化学
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环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2025
·
IF 21.1
Yi-Fan Qiao,Wen-Cui Li,Lei He,Jia Wang,Danhui Sun,Zihao Wang,An-Hui Lu
To efficiently convert ethanol into C 4+ olefins without an external hydrogen supply, this study designed an anatase-supported zinc oxide catalyst (ZnO/TiO 2 -A). Combining characterizations with kinetics measurements, we infer that the highly dispersed Zn-O-Ti sites efficiently promote ethanol dehydrogenation to acetaldehyde, which is identified as the rate-limiting step. Concurrently, Ti-O sites with strong C-C coupling ability convert acetaldehyde into high-carbon enal intermediates, which subsequently undergo hydrogenation and dehydration to yield C 4+ olefins with a high formation rate of 43.96 mmol C-atom ·g cat. −1 ·h −1 , outperforming most reported catalysts in the literature. Crucially, nuclear magnetic resonance spectroscopy analysis confirms that ethanol acts as an intrinsic hydrogen donor, supplying active hydrogen for the hydrogenation of C C and C O bonds in enal intermediates, thereby obviating the need for external hydrogen. This work presents a new strategy employing a non-precious metal oxide catalytic system for upgrading ethanol to high-value products.
研究领域:
催化化学
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能源化学
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材料化学
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有机转化
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绿色化学
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
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2020
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IF 4.551
Tingting Qi,Jing Shi,Xishuo Wang,Kun Dong,Yong Luo,Jiawei Teng,Guang-Wen Chu,Hai-Kui Zou,Baochang Sun
Hierarchical (micro/mesopore) ZSM-5 zeolites were hydrothermally synthesized in a rotating packed bed (RPB) which substantially enhances micromixing for the high viscosity reaction system. Herein, the effects of four operating processes with different micromixing intensity on nucleation/crystal growth process as well as physicochemical properties of ZSM-5 zeolites were investigated. Results indicate that enhancing micromixing by RPB in the zeolite synthesis could facilitate the formation of Al sites and shorten the nucleation and crystallization period. ZSM-5 samples prepared by RPB exhibit hierarchical structure, smaller average particle size, more uniform particle size distributions , larger specific surface areas, higher catalytic stability as well as more acid sites than those obtained by (stirring tank reactor) STR. While adopting the ZSM-5 samples prepared by RPB for catalyzing C4-olefin cracking reaction, the conversion of C4-olefin and yield of propylene are higher than those obtained by STR.
研究领域:
材料科学
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化学工程
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催化反应
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-9
·
IF 14.7
Liu Junhui,Xiong Hanting,Shuai Hua,Liu Xing,Peng Yong,Wang Lingmin,Wang Pengxiang,Zhao Zhiwei,Deng Zhenning,Zhou Zhenyu,Chen Jingwen,Chen Shixia,Zeng Zheling,Deng Shuguang,Wang Jun
Iso-butene (iso-C 4 H 8 ) is an important raw material in chemical industry, whereas its efficient separation remains challenging due to similar molecular properties of C 4 olefins. The ideal adsorbent should possess simultaneous high uptakes for 1,3-butadiene (C 4 H 6 ) and n-butene (n-C 4 H 8 ) counterparts, endowing high efficiency for iso-C 4 H 8 separation in adsorption columns. Herein, a sulfate-pillared adsorbent, SOFOUR-DPDS-Ni (DPDS = 4,4′-dipyridyldisulfide), is reported for the efficient iso-C 4 H 8 separation from binary and ternary C 4 olefin mixtures. The rigidity in pore sizes and shapes of SOFOUR-DPDS-Ni exerts the molecular sieving of iso-C 4 H 8 , while exhibiting high C 4 H 6 and n-C 4 H 8 uptakes. The benchmark Henry’s selectivity for C 4 H 6 /iso-C 4 H 8 (2321.8) and n-C 4 H 8 /iso-C 4 H 8 (233.5) outperforms most reported adsorbents. Computational simulations reveal the strong interactions for C 4 H 6 and n-C 4 H 8 . Furthermore, dynamic breakthrough experiments demonstrate the direct production of high-purity iso-C 4 H 8 (>99.9%) from C 4 H 6 /iso-C 4 H 8 (50/50, v / v ), n-C 4 H 8 /iso-C 4 H 8 (50/50, v / v ), and C 4 H 6 /n-C 4 H 8 /iso-C 4 H 8 (50/15/35, v / v / v ) gas-mixtures.
研究领域:
化学工程
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材料科学
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吸附技术
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
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IF 8.6
Zeyu Chang,Xiaoxia Jia,Tong Li,Yong Wang,Libo Li
In the petrochemical industry, the separation of C4 olefins is crucial but a challenging and energy-intensive process. In this study, two fluorinated anion-pillared hybrid ultramicroporous materials (HUMs), namely KAUST-7 (NbOFFIVE-1-Ni) and KAUST-8 (AlFFIVE-1-Ni), were explored for the efficient separation of ternary C4 olefin mixtures (C 4 H 6 /n-C 4 H 8 / iso -C 4 H 8 ) via gate-opening and size-sieving effects. KAUST-7, with a narrow and flexible pore window that completely excludes iso -C 4 H 8 , but allows for the absorption of C 4 H 6 and n-C 4 H 8 through gate-opening effects, with a preferential adsorption of C 4 H 6 due to its easier access to the channel. KAUST-8, on the other hand, with a larger pore window size and the strong H-bond interactions between the electronegative fluorine atoms from inorganic anion pillar and the C4 olefin molecules, efficiently separates iso -C 4 H 8 from C4 olefins, as the adsorption of both C 4 H 6 and n-C 4 H 8 is significantly enhanced while iso -C 4 H 8 retains much lower adsorption capacity. The relationship between the structures and separation properties of these materials is discussed, providing insight into the development of efficient separation materials. Fixed bed breakthrough experiments verify the excellent separation performances of KAUST-7 and KAUST-8 for C 4 H 6 /n-C 4 H 8 / iso -C 4 H 8 , highlighting their potential for industrial applications.
研究领域:
材料科学
·
石油化工
·
吸附分离技术
✓ 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）