MATERIALS CHEMISTRY AND PHYSICS
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2025
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IF 4.7
Quanhua Wang,Yuhao Zong,Yanchao Liu,Haixia Hu,Yanwei Yue,Xingxing Xie,Lixing Guo,Qingyuan Hu,Hu Wang,Jinke Li,Jiajun Shi,Lichen Zhang,Jiajun Zheng,Shuwei Chen
The design and development of a highly efficient and stable catalyst for styrene (ST) obtained from ethylbenzene (EB) dehydrogenation reaction is urgently required because a commercial Fe–K-based catalyst often undergoes severe deactivation resulted from the active phase decomposition into inactive ferrite compound at high temperatures (>600 °C). Herein, ultra-fine Al 2 O 3 nanofibers which are further self-assembled to form uniform rod-like morphology (R–Al 2 O 3 ) were fabricated via a facile sol-gel strategy and further utilized as support to dispersing vanadium species (V/R–Al 2 O 3 ). The physicochemical properties of the samples were systematically characterized by XRD, Raman, SEM, TEM, H 2 -TPR, CO 2 -TPD, XPS, and 27 Al MAS NMR techniques. It is found that except that R–Al 2 O 3 support has the merits of a high specific surface area, lager pore volume, and uniform mesopore structure, the presence of the unsaturated pentacoordinate Al 3+ ions plays a pivotal role in better dispersing V active species, with the existence of the isolate and/or polymeric forms. As compared to V/C–Al 2 O 3 (commercial Al 2 O 3 as support), the V/R–Al 2 O 3 catalyst endows outperformed catalytic performances for oxidative dehydrogenation of ethylbenzene in the presence of CO 2 (OEBDH-CO 2 ). In which, the V/R–Al 2 O 3 catalyst gives a high EB catalytic activity and good stability without significant deactivation phenomenon being detected even after the third regeneration test. Such a result can be principally ascribed to that R–Al 2 O 3 support with excellent textural properties can better disperse V species so as to expose more active sites, which is beneficial for improving the conversion efficiency of EB. More importantly, keeping/regaining high valence state of V species in the V/R–Al 2 O 3 catalyst under CO 2 as a soft oxidant effectively promotes Mars-Van Krevelen redox cycle, further suppressing the catalyst deactivation. This work provides a rational design strategy for a high efficiency and stable dehydrogenation catalyst by optimizing the textural properties of Al 2 O 3 support and introducing the unsaturated pentacoordinate Al 3+ ions.
研究领域:
催化化学
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材料科学
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DOI
高影响因子
Catalysis Science & Technology
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2021
·Vol. 12
·期 3
·962-968
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IF 6.119
Baining Lin,Yuwei Liu,Yaping Li,Fan Xu,Yingping Zou,Yonghua Zhou
Direct dehydrogenation of ethylbenzene to styrene catalyzed by metal-free materials is one of the most challenging topics in the chemical industry currently. Here, PBN@Al2O3(N) synthesized by in situ growth of phosphorus-doped boron nitride on commercial alumina is reported as a highly stable catalyst for at least 300 h with a stable ethylbenzene conversion of 93.51% and a styrene selectivity of over 95%, respectively. Control experiments and characterization indicated that the activity could be attributed to the combination of active sites on thin PBN layers and the boron-modified alumina surface, which enhanced the strength and amount of moderate acidic and basic sites. Besides, the even coverage of PBN on the porous alumina sphere ensured the excellent mass transfer of the reactant and product, leading to the obviously improved stability. The accessibility of commercial alumina and the facile synthesis technique made the catalyst an outstanding prospect for large-scale industrial application.
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
APPLIED CATALYSIS A-GENERAL
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2025
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IF 4.8
Yuan Ma,Baining Lin,Chaojun Guo,Yang Yang,Chuli Shi,Shuobin Fu,Yonghua Zhou
Non-metallic materials have attracted continuous interest in the direct dehydrogenation (DDH) of ethylbenzene due to their coke resistance and environmental friendliness. However, the catalytic activity was limited by the exposed density of active sites in non-metal catalysts. Herein, we report an atmosphere-pretreatment strategy using H 2 or O 2 at 350 ℃ to improve the exposure of active sites in Al 2 O 3 -supported phosphorus oxynitride (PNO) catalysts, thereby enhancing their catalytic performance in DDH of ethylbenzene. XPS, FTIR, and in situ DRIFTS analyses demonstrated that H 2 or O 2 pretreatment partially cleaved P–N bonds in the P 3 N 5 framework, inducing structural reorganization and exposing the inner N 2 P = O groups, thereby increasing the active site density. Among them, the H 2 -pretreated PNO/Al 2 O 3 catalyst (PNO/Al 2 O 3 -H) exhibited the highest N 2 P = O content (a 74.2 % increase compared with PNO/Al 2 O 3 ), which resulted in the highest catalytic activity ( X EB =58.5 %) under high-concentration ethylbenzene feed (12.2 vol%). This work demonstrates, for the first time, the application of atmosphere pretreatment to phosphorus-nitrogen catalysts and proposes a novel strategy for regulating the active site in dehydrogenation catalysis.
研究领域:
催化
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材料科学
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化学反应工程
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表面化学
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DOI
高影响因子
CATALYSIS LETTERS
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2022
·Vol. 153
·期 3
·921-930
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IF 2.936
Zhang Kai,Zhang Huanling,Feng Xipan,Wang Yue,Wang Guowei,Zhu Xiaolin,Li Chunyi
The catalytic activities of metal–based catalysts are largely dependent on the properties of their supports. The support (MgO, Al 2 O 3 , MgAl 2 O 4 , SiO 2, and CeO 2 ) effect of the Sn (1.2 wt%) based catalyst for the ethylbenzene dehydrogenation reaction was firstly investigated. The supported Sn-based catalysts were characterized by NH 3 -TPD, BET, XRD, and H 2 -TPR. Among the tested catalysts, the 1.2 Sn/CeO 2 catalyst presented the most effective catalytic activity, achieving a high ethylbenzene conversion of 56.2 wt% at 600 °C. The obvious support effect should originate from the electronic interaction between Sn and supports, instead of the geometric effect resulting from different dispersion of Sn species on carriers. The high activity of the 1.2 Sn/CeO 2 catalyst was attributed to the generation of oxygen vacancies on the CeO 2 surface. A typical strong metal-support interaction (SMSI) could be found in the 1.2 Sn/CeO 2 catalyst according to the comparison of H 2 -TPR, XPS, and Raman spectra result with pure CeO 2 support. The addition of Sn further promoted the generation of more oxygen vacancies by changing the redox properties of CeO 2 , and inhibited the agglomeration of CeO 2 nanoparticles, thereby enhancing greatly the catalyst's ethylbenzene dehydrogenation activity. Graphical Abstract
研究领域:
催化
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化学工程
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材料科学
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DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
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2021
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IF 5.876
Kai Zhang,Peipei Miao,Huanling Zhang,Yue Wang,Guowei Wang,Xiaolin Zhu,Chunyi Li
Background In the traditional ethylbenzene dehydrogenation process, much superheated steam is needed to ensure the activity and stability of the catalyst, inevitably leading to high energy consumption. Methods A novel ethylbenzene dehydrogenation process based on a circulating fluidized bed (CFB) reactor was used for the ethylbenzene dehydrogenation reaction under a low steam-to-oil ratio. In this work, a series of Fe-Al-based catalysts were prepared by a sol-gel method and the effect of alumina content on the catalytic performance of Fe-Al-based catalyst for ethylbenzene dehydrogenation was investigated. Significant findings Among a series of Fe-Al-based catalysts, the FeAl40 catalyst (the Fe-Al-based catalyst with 40 wt. % alumina) had the highest dehydrogenation activity and suitable attrition resistance for the CFB reactor. Further investigation found that the adding alumina could inhabit the formation of KFe 11 O 17 , leading to poor stability. Interestingly, the high activity of the FeAl40 catalyst could be completely recovered through a reaction-regeneration operation. Compared with the conventional ethylbenzene dehydrogenation process, the CFB process benefits from high activity, low steam-to-oil ratio and no induction period. Consequently, the FeAl40 catalyst had high dehydrogenation activity (∼51 wt. % yield of styrene) and low preparation cost, showing an extraordinary potential for industrial application.
研究领域:
化学工程
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催化
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过程工程
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产品关联
DOI
高影响因子
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