Post-synthesis of Sn-beta zeolite by aerosol method

Sn-beta zeolite is a Lewis acid catalyst which can activate the C-O and C[double bond, length as m-dash]O bonds of many organic compounds. In this paper, a simple aerosol method has been firstly applied to the post-synthesis of Sn-beta zeolite. The aqueous solution containing SnCl₂ and dealuminated beta zeolite was rapidly dried using an aerosol generator to obtain the Sn-beta zeolites with different Sn contents. The physicochemical properties of the Sn-beta zeolites were further characterized by XRD, nitrogen adsorption-desorption, FT-IR and Py-FT-IR techniques. The catalysts exhibited good catalytic performances in the Baeyer-Villiger oxidation reaction of cyclohexanone.

Rapid hydrothermal synthesis of hierarchical ZSM-5/beta composite zeolites

An innovative hydrothermal method has been successfully applied to the synthesis of hierarchical ZSM-5/beta composite zeolites with different mass ratios. Firstly, the ZSM-5 zeolites were coated with amorphous silica and aluminum species by a spray drying process. Then, the precursor powder was hydrothermally crystallized for only 1–2 days with the addition of tetraethyl ammonium hydroxide (TEAOH). The obtained products were characterized by XRD, SEM, TEM, N₂ physical adsorption–desorption, ²⁷Al MAS NMR, ICP, pyridine-IR and NH₃-TPD techniques. The characterization results imply that the ZSM-5/beta composite zeolites exhibit hierarchical-pores, higher external surface areas and larger mesopore volumes as compared to those of the pure ZSM-5 and beta zeolite. Moreover, the pore structure and acid sites of the ZSM-5/beta composite can be adjusted by changing the mass ratio of ZSM-5/beta. Finally, the ZSM-5/beta composite catalysts exhibit good catalytic performances in the cracking of 1,3,5-triisopropylbenzene (1,3,5-TIPB).

The hierarchical ZSM-5/beta composite zeolites synthesized via an innovative hydrothermal method exhibit superior catalytic performance in the cracking of 1,3,5-triisopropylbenzene.

Synthesis of mesoporous silicate molecular sieves by the aerosol-assisted method for loading and release of drug

The mesoporous silicate molecular sieves were synthesized with polyether F127 as the template by the aerosol-assisted method for loading and release of ibuprofen (IBU). The synthesized samples were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and N2 adsorption-desorption isotherms. The drug IBU was applied as a model drug to investigate the drug release behaviour by ultraviolet spectrophotometry measurements. The investigation results demonstrate that mesoporous silicate molecular sieves by the aerosol-assisted method are spherical with a core-shell structure. As the drug carrier, it has good structural stability and can achieve drug controlled release which is expected. It exhibits safety to a certain degree. Therefore, the aerosol-assisted synthesis method provides a new idea for the synthesis of sustained-release drug carriers.

The synthesis of hierarchical high-silica beta zeolites in NaF media

Hierarchical high-silica beta zeolites were synthesized using an aerosol assisted hydrothermal method in NaF media.

Aerosol processing: a wind of innovation in the field of advanced heterogeneous catalysts

Aerosol processing technologies represent a major route of innovation in the mushrooming field of heterogeneous catalysts preparation.

Innovative Sol-Gel Routes for the Bottom-Up Preparation of Heterogeneous Catalysts

Heterogeneous catalysts can be prepared by different methods offering various levels of control on the final properties of the solid. In this account, we exemplify bottom-up preparation routes that are based on the sol-gel chemistry and allow to tailor some decisive properties of solid catalysts. First, an emulsion templating strategy is shown to lead to macrocellular self-standing monoliths with a macroscopic 3D structure. The latter can be used as catalyst or catalyst supports in flow chemistry, without requiring any subsequent shaping step. Second, the aerosol-assisted sol-gel process allows for the one-step and continuous production of porous mixed oxides. Tailored textural properties can be obtained together with an excellent control on composition and homogeneity. Third, the application of non-hydrolytic sol-gel routes, in the absence of water, leads to mixed oxides with outstanding textural properties and with peculiar surface chemistry. In all cases, the resulting catalytic performance can be correlated with the specificities of the preparation routes presented. This is exemplified in catalytic reactions in the fields of biomass conversion, petro chemistry, enantioselective organic synthesis, and air pollution mitigation.

Precise control of the size of zeolite B-ZSM-5 based on seed surface crystallization

A unified functionD³=d³D₀³/[xD₀³+ (1 −x)d³] is established to precise control and predict the particle size of B-ZSM-5 from 153 nm to 14.2 μm in the TPABr and/or TPAOH synthetic systems.