SAPO-34 catalyst with plate-like morphology was designed and synthesized for the first time, by the dry gel conversion method using cheap triethylamine as a structure-directing agent assisted with seed suspension cont...SAPO-34 catalyst with plate-like morphology was designed and synthesized for the first time, by the dry gel conversion method using cheap triethylamine as a structure-directing agent assisted with seed suspension containing nanosheet-like SAPO-34 seed. The latter played an important role in formation of SAPO-34 （CHA-type） with plate-like morphology. In addition, the yield of the product in the synthesis system containing seed suspension reached 97%, 15% higher than that obtained in the corre- sponding synthesis system without the seed suspension. Meanwhile, the plate-like SAPO-34 catalysts synthesized by this method exhibited higher selectivity to light olefins and longer lifetime in methanol-to-olefins （MTO） reaction than the traditional cubic SAPO-34 catalyst. This work provides a new technical route for green and efficient synthesis of SAPO-34 catalysts with improved MTO performance.展开更多
Nanocrystalline zirconium（IV） oxide （nc-ZrO2） possessing high surface area was synthesized by a low tem- perature eco-friendly solution combustion method using a new organic fuel alanine. The powder XRD, SEM and s...Nanocrystalline zirconium（IV） oxide （nc-ZrO2） possessing high surface area was synthesized by a low tem- perature eco-friendly solution combustion method using a new organic fuel alanine. The powder XRD, SEM and surface area measurements were carried out for characterization of nc-ZrO2. The powder XRD results revealed that, the nc-ZrO2 has the pure tetragonal phase. The crystallite size calculated by Scherrer＇s formula and BET surface area were found to be ca. 53--57 nm and ca. 275 m2/g, respectively. SEM micrograph exhibited the macroporous nature of the powder, nc-ZrO2 has been employed as a catalyst for the solvent-free synthesis of 3,4-dihydro- pyrimidin-2-ones （DHPMs） by a microwave （MW） assisted one-pot, multicomponent Biginelli condensation reaction of araldehydes, ethylacetoacetate and urea or thiourea. DHPMs are obtained in good to excellent yields （85%-- 96%） under this reaction condition within short interval of time （10--20 min）.展开更多
A novel electrochemical multicomponent cascade reaction of indole-tethered alkenes with CF_(3)SO_(2)Na and n-BuaNI has been developed,which enables the rapid assembly of spiropyrrolidinyl-oxindoles in good yields.The ...A novel electrochemical multicomponent cascade reaction of indole-tethered alkenes with CF_(3)SO_(2)Na and n-BuaNI has been developed,which enables the rapid assembly of spiropyrrolidinyl-oxindoles in good yields.The experimental results and DFT calculations suggest that this reaction proceeds through the oxidation of CF_(3)SO_(2)Na,radical coupling with alkene,spirocyclization,oxidation of sulfinate,iodide substitution,and water coupling.This strategy features mild reaction conditions,easy-to-handle reactants,and good chemical yields.This finding not only enriches the research contents of indole-tethered alkenes but also provides a green strategy for the construction of spiropyrrolidinyl-oxindoles compared with the existing methodologies.展开更多
文摘SAPO-34 catalyst with plate-like morphology was designed and synthesized for the first time, by the dry gel conversion method using cheap triethylamine as a structure-directing agent assisted with seed suspension containing nanosheet-like SAPO-34 seed. The latter played an important role in formation of SAPO-34 （CHA-type） with plate-like morphology. In addition, the yield of the product in the synthesis system containing seed suspension reached 97%, 15% higher than that obtained in the corre- sponding synthesis system without the seed suspension. Meanwhile, the plate-like SAPO-34 catalysts synthesized by this method exhibited higher selectivity to light olefins and longer lifetime in methanol-to-olefins （MTO） reaction than the traditional cubic SAPO-34 catalyst. This work provides a new technical route for green and efficient synthesis of SAPO-34 catalysts with improved MTO performance.
文摘Nanocrystalline zirconium（IV） oxide （nc-ZrO2） possessing high surface area was synthesized by a low tem- perature eco-friendly solution combustion method using a new organic fuel alanine. The powder XRD, SEM and surface area measurements were carried out for characterization of nc-ZrO2. The powder XRD results revealed that, the nc-ZrO2 has the pure tetragonal phase. The crystallite size calculated by Scherrer＇s formula and BET surface area were found to be ca. 53--57 nm and ca. 275 m2/g, respectively. SEM micrograph exhibited the macroporous nature of the powder, nc-ZrO2 has been employed as a catalyst for the solvent-free synthesis of 3,4-dihydro- pyrimidin-2-ones （DHPMs） by a microwave （MW） assisted one-pot, multicomponent Biginelli condensation reaction of araldehydes, ethylacetoacetate and urea or thiourea. DHPMs are obtained in good to excellent yields （85%-- 96%） under this reaction condition within short interval of time （10--20 min）.
基金the financial supports from the National Natural Science Foundation of China(No.21761132021).
文摘A novel electrochemical multicomponent cascade reaction of indole-tethered alkenes with CF_(3)SO_(2)Na and n-BuaNI has been developed,which enables the rapid assembly of spiropyrrolidinyl-oxindoles in good yields.The experimental results and DFT calculations suggest that this reaction proceeds through the oxidation of CF_(3)SO_(2)Na,radical coupling with alkene,spirocyclization,oxidation of sulfinate,iodide substitution,and water coupling.This strategy features mild reaction conditions,easy-to-handle reactants,and good chemical yields.This finding not only enriches the research contents of indole-tethered alkenes but also provides a green strategy for the construction of spiropyrrolidinyl-oxindoles compared with the existing methodologies.
