Hollow zeolite microspheres have recently attracted much attention for their applications in catalysis,microreactors and biomedicine.Herein,we present hierarchically structured zeolite ZSM-5 microspheres with unique,a...Hollow zeolite microspheres have recently attracted much attention for their applications in catalysis,microreactors and biomedicine.Herein,we present hierarchically structured zeolite ZSM-5 microspheres with unique,abundant macropores that allow more efficient use for catalysis.The hierarchically macroporous zeolite ZSM-5 microspheres are synthesized under the assistance of water/oil emulsions and using polystyrene nanospheres as templates.The zeolite microsphere is assembled by uniform hollow zeolite nanospheres.Their large inner cavities and thin zeolite shells lead to smaller diffusion channel and higher improved accessibility to active sites,contributing to high catalytic performance in the catalytic conversion of benzyl alcohol in mesitylene.Such novel zeolite microspheres with impressive performance will be applied to numerous other industrial catalytic reactions.展开更多
Self‐supporting ZSM‐5crystals with hierarchical porosity were prepared through a steam‐assisted crystallization method using sponges as rigid scaffolds.The synthesized materials were characterized by X‐ray diffrac...Self‐supporting ZSM‐5crystals with hierarchical porosity were prepared through a steam‐assisted crystallization method using sponges as rigid scaffolds.The synthesized materials were characterized by X‐ray diffraction,nitrogen sorption,scanning electron microscopy,transmission electron microscopy,solid‐state nuclear magnetic resonance spectroscopy and ammonia temperature‐programmed desorption.The ZSM‐5monoliths exhibited high crystallinities,hierarchical porous structures and strong acidities.They showed superior catalytic performance in the liquid‐phase esterification reaction between benzyl alcohol and hexanoic acid.展开更多
Modified hierarchical porous Hβ zeolite was obtained by metal modification of Hβ zeolite, which was treated with alkaline solution, and the catalysts before and after modification were characterized by means of X-ra...Modified hierarchical porous Hβ zeolite was obtained by metal modification of Hβ zeolite, which was treated with alkaline solution, and the catalysts before and after modification were characterized by means of X-ray diffraction(XRD), nitrogen adsorption-desorption~ scanning electron microscopy(SEM), X-ray fluorescence(XRF), NH3 temperature-programmed desorption and Fourier-transform infrared spectroscopy(FTIR). The activities of acy- lation of anisole with acetic anhydride were also investigated. The results show that the Hp zeolite, which was treated with alkaline solution has microporous and mesoporous structures that could improve the diffusion performance of chemical reaction. The amount of acid was modulated with metal modification. The Hβ zeolite modified by 5%(mass fraction) metal chromium had the best catalytic performance. The conversion of acetic anhydride acylation was 93.01% under the optimal conditions, which was higher than that of other catalysts. The catalyst not only showed good activity, but also exhibited a stable performance in regeneration tests.展开更多
Hierarchical porous zeolitic imidazolate frameworks (ZIFs) have potential for adsorption, catalysis and chemical sensing applications. Ultrafast synthesis of ZIFs at room temperature and pressure is particularly des...Hierarchical porous zeolitic imidazolate frameworks (ZIFs) have potential for adsorption, catalysis and chemical sensing applications. Ultrafast synthesis of ZIFs at room temperature and pressure is particularly desirable for large-scale industrial production. Here, we developed a green and versatile method using organic amines as supramolecular templates (organic amine-template) to rapidly synthesize hierarchical porous ZIFs (ZIF-8, ZIF-61 and ZIF-90) at room temperature and pressure. The synthesis time was reduced dramatically to within 1 min, and the resulting ZIFs had multimodal hierarchical porous structures with mesopores/ macropores interconnected with micropores. Notably, the space-time yield (STY) of hierarchical porous ZIF-8 was up to 1.29×10^4 kg m^-3 d^-1, which is more than three times higher than that reported using other methods. Furthermore, the morphologies and porosities of the produced ZIFs could be readily tuned by controlling the synthesis time or type of organic amine. The organic amine played two roles in the synthesis: (1) a protonation agent to deprotonate organic ligands, facilitating the formation of ZIF crystals, and (2) an structure directing agent to direct mesopore/macropore formation. The resulting hierarchical porous ZIF-8 exhibited enhanced uptake capacities and diffusion rates for guest molecules relative to its microporous counterpart. This work provides a new direction for the green and efficient synthesis of various hierarchical porous ZIFs with high STYs for a wide range of applications.展开更多
The development of a simple and facile synthesis route is a highly desirable but challenging process in the fabrication of nanoscale hierarchical porous zeolitic imidazolate frameworks(ZIFs).Herein we describe a facil...The development of a simple and facile synthesis route is a highly desirable but challenging process in the fabrication of nanoscale hierarchical porous zeolitic imidazolate frameworks(ZIFs).Herein we describe a facile method for rapidly synthesizing hierarchically porous ZIF-90 nanocrystals(particle sizes of~300 nm)using hydroxyl double salts as intermediates at room temperature.The as-synthesized ZIF-90 contained hierarchical porous structures developed using a crystalline interior and a random stack of multiple nanoparticles.Both the morphology and particle size of ZIF-90 nanocrystals could be tuned by controlling the molar ratio of ICA/Zn^(2+).Note that the as-synthesized hierarchically porous ZIF-90 nanocrystals exhibited higher thermal stability compared with the conventional ZIF-90.Because of the introduction of hierarchical porous structures,the resultant hierarchically porous ZIF-90 nanocrystals showed enhanced toluene adsorption capacity than those of conventional metal organic frameworks and zeolites.展开更多
Trimodal hierarchical yolk-shell materials consisting of TS-1 core and mesoporous carbon shell (YS-TS- I@MC) was successfully synthesized by using TS-l@mesosilica as hard template, sucrose as carbon source and organ...Trimodal hierarchical yolk-shell materials consisting of TS-1 core and mesoporous carbon shell (YS-TS- I@MC) was successfully synthesized by using TS-l@mesosilica as hard template, sucrose as carbon source and organic base tetrapropylammonium hydroxide (TPAOH) as silica etching agent. The resultant YS-TS-I@MC contains the micropores (0.51 nm) in TS-1 core, the mesopores (2.9 rim) in carbon shell as well as a void or a stack pore between TS-1 fragements (TS-1 intercrystal mesopores, -18.4 nm). Under the rigorous etching conditions, the crystalline structure of TS-1 core was well retained. The YS-TS- I@MC served as a good support for palladium nano-particles (Pd NPs) or Rh(OH)x species, giving rise to efficient bifunctional catalysts for the tandem reactions including one-pot synthesis of propylene oxide or amides.展开更多
基金supported by the National Key R&D Program of China(No.2022YFB3504000)the National Natural Science Foundation of China(Nos.22302152,U20A20122,22293020,U22B6011)+3 种基金the Fundamental Research Funds for the Central Universities,China(WUT:2024IVA090)the Program of Introducing Talents of Discipline to Universities-Plan 111(No.B20002)from the Ministry of Science and Technology and the Ministry of Education of ChinaThis research was also supported by the European Commission Interreg V France-Wallonie-Vlaanderen Project“DepollutAir”,the Program Win2Wal(No.TCHARBONACTIF:2110120)Wallonia Region of Belgium and the National Key R&D Program Intergovernmental Technological Innovation Special Cooperation Project Wallonia-Brussels/China(MOST)(No.SUB/2021/IND493971/524448).
文摘Hollow zeolite microspheres have recently attracted much attention for their applications in catalysis,microreactors and biomedicine.Herein,we present hierarchically structured zeolite ZSM-5 microspheres with unique,abundant macropores that allow more efficient use for catalysis.The hierarchically macroporous zeolite ZSM-5 microspheres are synthesized under the assistance of water/oil emulsions and using polystyrene nanospheres as templates.The zeolite microsphere is assembled by uniform hollow zeolite nanospheres.Their large inner cavities and thin zeolite shells lead to smaller diffusion channel and higher improved accessibility to active sites,contributing to high catalytic performance in the catalytic conversion of benzyl alcohol in mesitylene.Such novel zeolite microspheres with impressive performance will be applied to numerous other industrial catalytic reactions.
基金supported by the National Natural Science Foundation of China(21333009)the Youth Innovation Promotion Association of CAS(2017049)~~
文摘Self‐supporting ZSM‐5crystals with hierarchical porosity were prepared through a steam‐assisted crystallization method using sponges as rigid scaffolds.The synthesized materials were characterized by X‐ray diffraction,nitrogen sorption,scanning electron microscopy,transmission electron microscopy,solid‐state nuclear magnetic resonance spectroscopy and ammonia temperature‐programmed desorption.The ZSM‐5monoliths exhibited high crystallinities,hierarchical porous structures and strong acidities.They showed superior catalytic performance in the liquid‐phase esterification reaction between benzyl alcohol and hexanoic acid.
基金Supported by the Natural Science Foundation of Technology Department of Liaoning Province, China(No.2014020109).
文摘Modified hierarchical porous Hβ zeolite was obtained by metal modification of Hβ zeolite, which was treated with alkaline solution, and the catalysts before and after modification were characterized by means of X-ray diffraction(XRD), nitrogen adsorption-desorption~ scanning electron microscopy(SEM), X-ray fluorescence(XRF), NH3 temperature-programmed desorption and Fourier-transform infrared spectroscopy(FTIR). The activities of acy- lation of anisole with acetic anhydride were also investigated. The results show that the Hp zeolite, which was treated with alkaline solution has microporous and mesoporous structures that could improve the diffusion performance of chemical reaction. The amount of acid was modulated with metal modification. The Hβ zeolite modified by 5%(mass fraction) metal chromium had the best catalytic performance. The conversion of acetic anhydride acylation was 93.01% under the optimal conditions, which was higher than that of other catalysts. The catalyst not only showed good activity, but also exhibited a stable performance in regeneration tests.
基金supported by the National Natural Science Foundation of China (21576094)SRFDP (20130172110012)the Fundamental Research Funds for the Central Universities (2015ZM046)
文摘Hierarchical porous zeolitic imidazolate frameworks (ZIFs) have potential for adsorption, catalysis and chemical sensing applications. Ultrafast synthesis of ZIFs at room temperature and pressure is particularly desirable for large-scale industrial production. Here, we developed a green and versatile method using organic amines as supramolecular templates (organic amine-template) to rapidly synthesize hierarchical porous ZIFs (ZIF-8, ZIF-61 and ZIF-90) at room temperature and pressure. The synthesis time was reduced dramatically to within 1 min, and the resulting ZIFs had multimodal hierarchical porous structures with mesopores/ macropores interconnected with micropores. Notably, the space-time yield (STY) of hierarchical porous ZIF-8 was up to 1.29×10^4 kg m^-3 d^-1, which is more than three times higher than that reported using other methods. Furthermore, the morphologies and porosities of the produced ZIFs could be readily tuned by controlling the synthesis time or type of organic amine. The organic amine played two roles in the synthesis: (1) a protonation agent to deprotonate organic ligands, facilitating the formation of ZIF crystals, and (2) an structure directing agent to direct mesopore/macropore formation. The resulting hierarchical porous ZIF-8 exhibited enhanced uptake capacities and diffusion rates for guest molecules relative to its microporous counterpart. This work provides a new direction for the green and efficient synthesis of various hierarchical porous ZIFs with high STYs for a wide range of applications.
基金the National Natural Science Foundation of China(No.21576094)the Guangdong Natural Science Foundation(No.2017A030313052)the Guangdong Basic and Applied Basic Research Foundation(Nos.2019A1515110706,2019A1515110259 and 2019A1515110535)。
文摘The development of a simple and facile synthesis route is a highly desirable but challenging process in the fabrication of nanoscale hierarchical porous zeolitic imidazolate frameworks(ZIFs).Herein we describe a facile method for rapidly synthesizing hierarchically porous ZIF-90 nanocrystals(particle sizes of~300 nm)using hydroxyl double salts as intermediates at room temperature.The as-synthesized ZIF-90 contained hierarchical porous structures developed using a crystalline interior and a random stack of multiple nanoparticles.Both the morphology and particle size of ZIF-90 nanocrystals could be tuned by controlling the molar ratio of ICA/Zn^(2+).Note that the as-synthesized hierarchically porous ZIF-90 nanocrystals exhibited higher thermal stability compared with the conventional ZIF-90.Because of the introduction of hierarchical porous structures,the resultant hierarchically porous ZIF-90 nanocrystals showed enhanced toluene adsorption capacity than those of conventional metal organic frameworks and zeolites.
基金the National Natural Science Foundation of China(No.21273076,U1162102)the National Key Technology R&D Program(No.2012BAE05B02)+1 种基金Ph.D Programs Foundation of Ministry of Education(No.2012007613000)the Shanghai Leading Academic Discipline Project(B409)
文摘Trimodal hierarchical yolk-shell materials consisting of TS-1 core and mesoporous carbon shell (YS-TS- I@MC) was successfully synthesized by using TS-l@mesosilica as hard template, sucrose as carbon source and organic base tetrapropylammonium hydroxide (TPAOH) as silica etching agent. The resultant YS-TS-I@MC contains the micropores (0.51 nm) in TS-1 core, the mesopores (2.9 rim) in carbon shell as well as a void or a stack pore between TS-1 fragements (TS-1 intercrystal mesopores, -18.4 nm). Under the rigorous etching conditions, the crystalline structure of TS-1 core was well retained. The YS-TS- I@MC served as a good support for palladium nano-particles (Pd NPs) or Rh(OH)x species, giving rise to efficient bifunctional catalysts for the tandem reactions including one-pot synthesis of propylene oxide or amides.