Titanosilicate zeolites are an important class of heterogeneous catalysts that are widely used in several catalytic processes.The construction of hierarchical titanosilicate zeolites(e.g.,TS-1 with an MFI structure)is...Titanosilicate zeolites are an important class of heterogeneous catalysts that are widely used in several catalytic processes.The construction of hierarchical titanosilicate zeolites(e.g.,TS-1 with an MFI structure)is of great interest as they can promote the mass transportation and molecular accessibility of reactant molecules.Herein,we presented a temperature-regulated method to construct anatase-free hierarchical TS-1 zeolite catalysts by utilizing a two-step hydrothermal crystallization strategy with tetrabutylammonium hydroxide(TBAOH)as the sole organic structure-directing agent.The two-step crystallization process,i.e.,initial crystallization at lower temperature followed by secondary crystallization at higher temperature,afforded the incorporation of more active Ti species into TS-1 and the formation of hierarchical structures resulting from the layer-stacking growth.The prepared hierarchical TS-1 zeolite catalysts showed superior catalytic performance in the oxidative desulfurization of bulky organosulfur compound dibenzothiophene compared with their microporous counterpart,giving a higher turnover number(23.5 vs.1.7).The temperature-based kinetic regulation approach offers an effective way to construct hierarchical titanosilicate zeolite catalysts with controllable active Ti atoms.展开更多
The growth of bulk nonlinear optical(NLO)crystals that exhibit robust second harmonic generation(SHG)is currently an intriguing and rapidly advancing field for laser and photonic applications.Among the various options...The growth of bulk nonlinear optical(NLO)crystals that exhibit robust second harmonic generation(SHG)is currently an intriguing and rapidly advancing field for laser and photonic applications.Among the various options available,organic-inorganic hybrid materials offer numerous possibilities due to their distinctive amalgamation of inorganic coordinate frameworks and organic molecules.Herein,we have successfully developed a novel non-centrosymmetric(NCS)organic-inorganic hybrid NLO material,manganese mercury thiocyanate-bis(acetamide),[Mn(CH_(3)CONH_(2))_(2)][Hg(SCN)_(4)](MMTA),by synergistically incorporating inorganic polyhedra and organic conjugated molecules.The crystal displays a polar architecture comprising an asymmetric[HgS_(4)]tetrahedron and[MnN_(4)O_(2)]octahedron,which are connected by fourπ-conjugated-S-CuN-ligands.More intriguingly,inch-sized single crystals with dimensions up to 50×50×12 mm^(3) have been easily grown from aqueous solutions by a temperature-lowering method.The optical property investigation suggests that MMTA is a phase-matching NLO material with a large SHG response approximately 2.5 times that of KH_(2)PO_(4),demonstrating its potential for NLO applications.Based on a combination of structural analysis and theoretical calculations,it is suggested that the significant SHG response can be attributed to the cooperative interaction between conjugated organic molecules and a highly asymmetric inorganic distorted octahedron.This work introduces an effective approach for the discovery of high-performance quadratic NLO materials,with a particular focus on organic-inorganic hybrid compounds.展开更多
基金the National Key Research and Development Program of China(Grant 2016YFB0701100)the National Natural Science Foundation of China(Grant 21920102005,21621001,and 21835002)+2 种基金the 111 Project of China(B17020)for supporting this workThe support from National Major Scientific Instruments and Equipments Development Project of National Natural Science Foundation of China(Grant 2152780065)is also acknowledgedR.B.also acknowledges the Graduate Interdisciplinary Research Funding of Jilin University(10183201815).
文摘Titanosilicate zeolites are an important class of heterogeneous catalysts that are widely used in several catalytic processes.The construction of hierarchical titanosilicate zeolites(e.g.,TS-1 with an MFI structure)is of great interest as they can promote the mass transportation and molecular accessibility of reactant molecules.Herein,we presented a temperature-regulated method to construct anatase-free hierarchical TS-1 zeolite catalysts by utilizing a two-step hydrothermal crystallization strategy with tetrabutylammonium hydroxide(TBAOH)as the sole organic structure-directing agent.The two-step crystallization process,i.e.,initial crystallization at lower temperature followed by secondary crystallization at higher temperature,afforded the incorporation of more active Ti species into TS-1 and the formation of hierarchical structures resulting from the layer-stacking growth.The prepared hierarchical TS-1 zeolite catalysts showed superior catalytic performance in the oxidative desulfurization of bulky organosulfur compound dibenzothiophene compared with their microporous counterpart,giving a higher turnover number(23.5 vs.1.7).The temperature-based kinetic regulation approach offers an effective way to construct hierarchical titanosilicate zeolite catalysts with controllable active Ti atoms.
基金support of the National Natural Science Foundation of China(no.22375201,22031009,and 21921001).
文摘The growth of bulk nonlinear optical(NLO)crystals that exhibit robust second harmonic generation(SHG)is currently an intriguing and rapidly advancing field for laser and photonic applications.Among the various options available,organic-inorganic hybrid materials offer numerous possibilities due to their distinctive amalgamation of inorganic coordinate frameworks and organic molecules.Herein,we have successfully developed a novel non-centrosymmetric(NCS)organic-inorganic hybrid NLO material,manganese mercury thiocyanate-bis(acetamide),[Mn(CH_(3)CONH_(2))_(2)][Hg(SCN)_(4)](MMTA),by synergistically incorporating inorganic polyhedra and organic conjugated molecules.The crystal displays a polar architecture comprising an asymmetric[HgS_(4)]tetrahedron and[MnN_(4)O_(2)]octahedron,which are connected by fourπ-conjugated-S-CuN-ligands.More intriguingly,inch-sized single crystals with dimensions up to 50×50×12 mm^(3) have been easily grown from aqueous solutions by a temperature-lowering method.The optical property investigation suggests that MMTA is a phase-matching NLO material with a large SHG response approximately 2.5 times that of KH_(2)PO_(4),demonstrating its potential for NLO applications.Based on a combination of structural analysis and theoretical calculations,it is suggested that the significant SHG response can be attributed to the cooperative interaction between conjugated organic molecules and a highly asymmetric inorganic distorted octahedron.This work introduces an effective approach for the discovery of high-performance quadratic NLO materials,with a particular focus on organic-inorganic hybrid compounds.
