Shuangqin Zeng

NiWO4 nanoparticles: a promising catalyst for hydrodesulfurization

NiWO(4) nanoparticles have been facilely synthesized by a hydrothermal approach, and used as a catalyst for the hydrodesulfurization of thiophene and its derivative 4,6-dimethyldibenzothiophene, showing a significantly higher activity than commercial NiW/Al(2)O(3).

Relevant parameters for obtaining high-surface area materials by delamination of magadiite, a layered sodium silicate

Layered silicates can be used for the preparation of high surface area materials by intercalation with organic cations followed by ultrasonication. The relevant parameters for delamination (exfoliation) of cetyltrimethylammonium bromide exchange magadiite are investigated. Using a magadiite wet cake, performing the delamination in water and recovering the solid phase by acidification allow increasing the surface area of the final material by a factor of ca. 20 (553 vs. 30 m2 g−1) compared to the standard procedure. The role of each step is analysed and the material resulting from the optimised procedure can be described as creased silicate layers. This results in a microporous–mesoporous material with about 60% of the surface in pores larger than 2.0 nm.

Influence of tungsten sources on the synthesis and properties of ammonium dioxothiotungstate

Ammonium dioxothiotungstate was synthesized using different tungsten sources and characterized in detail by powder X-ray diffraction, energy dispersive X-ray spectrometry, transmission electron microscopy, nitrogen adsorption, and temperature-programmed sulfidation. It was found that tungsten oxide nanobelts are superior to ammonium metatungstate as tungsten source for the synthesis of ammonium dioxothiotungstate due to a time-consuming aging step being excluded from the synthesis route. Moreover, detailed characteristic data reveal that, when tungsten oxide nanobelts are used, the physical and chemical properties of the resulting ammonium dioxothiotungstate including particles size, specific surface area, and sulfidation pattern were improved. Also, the hydrodesulfurization measurements showed higher catalytic activity and balanced selectivity of the resulting ammonium dioxothiotungstate.