Chunying Han

In situ synthesis, characterization, and catalytic performance of tungstophosphoric acid encapsulated into the framework of mesoporous silica pillared clay

Mesoporous silica pillared clay (SPC) incorporated with tungstophosphoric acid (HPW) has been synthesized via in situ introducing P and W source in the acidic suspension of the clay interlayer template during the formation of the silica pillared clay. The samples were characterized by XRD, XRF, FT-IR, TG-DTA, N(2) adsorption-desorption, and SEM techniques. The results showed that the HPW formed by in situ method has been effectively introduced into the framework of mesoporous silica pillared clay and its Keggin structure remained perfectly after formation of the materials. In addition, samples with similar HPW loadings were also prepared by impregnation method using SPC as the support. HPW in the incorporated samples was better dispersed into the silica pillared clay than in the impregnated samples. The results of catalytic tests indicated that the encapsulated materials demonstrated better catalytic performance than the impregnated samples in oxidative desulfurization (ODS) of dibenzothiophene (DBT).

Hierarchical porous nano-MFI zeolite-pillared montmorillonite clay synthesized by recrystallization for hydrocracking of residual oil

An MFI zeolite nanosheet-pillared montmorillonite clay (MPC) composite material has been synthesized under hydrothermal conditions by a recrystallization method. The hierarchical porous material possesses uniform micropores in the crystalline zeolite pillars and uniform mesopores between the zeolite pillars in the clay interlayer galleries. The MPC material exhibited higher activity and better selectivity in hydrocracking of residual oil than either MFI or the montmorillonite clay pillared with silica (SPC) or the mixture of both.

Bimetallic V and Ti incorporated MCM-41 molecular sieves and their catalytic properties

A series of bimetallic mesostructured V–Ti–MCM-41 molecular sieves with high surface area and narrow pore-size distribution were obtained by a hydrothermal crystallization method. The obtained products were characterized by a series of techniques including X-ray fluorescence, X-ray diffraction, high-resolution transmission electron microscopy, N2 adsorption–desorption, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy and diffuse reflectance ultraviolet-visible spectroscopy. Characterization results showed that the V–Ti–MCM-41 samples remain in a relatively ordered hexagonal structure. V and Ti atoms were incorporated into the silicon framework. The highest phenol selectivity of 94.7% and benzene conversion of 22.3% are obtained over the 3V–5Ti–MCM-41 sample using H2O2 as an oxidant. In addition, the catalytic performance did not decrease after being recycled four times.