Hierarchical HZSM-5 for Catalytic Cracking of Oleic Acid to Biofuels

Solid acid catalyzed cracking of waste oil-derived fatty acids is an attractive route to hydrocarbon fuels. HZSM-5 is an effective acid catalyst for fatty acid cracking; however, its microporous nature is susceptible to rapid deactivation by coking. We report the synthesis and application of hierarchical HZSM-5 (h-HZSM-5) in which silanization of pre-crystallized zeolite seeds is employed to introduce mesoporosity during the aggregation of growing crystallites. The resulting h-HZSM-5 comprises a disordered array of fused 10–20 nm crystallites and mesopores with a mean diameter of 13 nm, which maintain the high surface area and acidity of a conventional HZSM-5. Mesopores increase the yield of diesel range hydrocarbons obtained from oleic acid deoxygenation from ~20% to 65%, attributed to improved acid site accessibility within the hierarchical network.

The mechanism of promoter-induced zeolite nanosheet crystallization under hydrothermal and microwave irradiation conditions

The mechanism of MFI zeolite nanosheet formation was established under accelerated conditions using perchlorate ions and fresh zeolite seeds as promoters.

Cubic Pm3n mesoporous aluminosilicates assembled from zeolite seeds as strong acidic catalysts

Cubic Pm3n mesoporous aluminosilicates with 3D interconnected pore structures, assembled from Al-incorporating ZSM-5 seeds at pH 9 using CTEABr as a pore-directing agent, are efficient catalysts for the alkylation of 2,4-di-tert-butylphenol with cinnamyl alcohol to form flavan.

Solvent-free synthesis of titanosilicate zeolites

Titanosilicate zeolites with MFI and *BEA structures are successfully synthesized using raw materials of fumed silica, titanium sulfate, organic templates, and zeolite seeds in the absence of solvents.

The Preparation and Characterization of Zeolite LTA Membrane with Microwave-Assisted Method

A facial method to prepare zeolite LTA membrane via microwave-assisted heating method was reported. The A-type zeolite seeds were prepared by hydrothermal method from a precursor solution composed of A2O3:SiO2:Na2O:H2O with molar ratio of 1:5:40:1000. The optimized process parameters for synthesizing the zeolite seeds are reaction for 10 min, microwave power of 135 W, and the ratio of H2O/Na2O is 25. Zeolite LTA membrane was prepared via secondary growth method by microwave heating on the silicane and zeolite seed modified ceramic supports. The prepared zeolite seeds and membrane were characterized with X-ray diffraction (XRD), Fourier Transform Infrared (FT-IR) and scanning electron microscopy (SEM). The results show that the size of the zeolite seeds are in the range of 100-400 nm with regular cubic morphology, and the zeolite membrane have homogeneous thickness of 1.5 μm and perfect morphology without defects and pinholes. The easy operation and controllable process make the zeolite membrane by this method properly have wide application for the gas sensor and devices.