Yinyong Sun

Ti-containing hierarchical Beta with highly active sites for deep desulfurization of fuels under mild conditions

The deep desulfurization of fuels has attracted much attention, due to the stringent demands of environmental regulations. In this work, we report for the first time that Ti-containing hierarchical Beta prepared by a post-synthetic method was utilized as a catalyst for the deep oxidative desulfurization (ODS) of fuels. It was found that the dealumination of Beta before the introduction of Ti species may greatly enhance the ODS activity of Ti-containing hierarchical Beta in the ODS reactions of both dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT). The Ti-containing hierarchical Beta (Ti-B-M-DA) prepared by desilication–dealumination processes exhibited much better ODS activity than that obtained by direct desilication or dealumination. The TOF number over Ti-B-M-DA reached 58.8 h−1 in the ODS of DBT at 333 K and ambient pressure. More importantly, Ti-B-M-DA exhibited highly active catalytic performance in the ODS of 4,6-DMDBT. The TOF number reached 27.1 h−1 under mild conditions, suggesting that it has the potential for application in deep oxidative desulfurization. Such outstanding catalytic performance could be attributed to the presence of highly active sites and rich mesoporosity in Ti-containing hierarchical Beta.

Enhancement of Oxidative Desulfurization Performance over UiO-66(Zr) by Titanium Ion Exchange

Oxidative desulfurization is considered to be one of the most promising methods for producing ultra-low-sulfur fuels because it can effectively remove refractory sulfur-containing aromatic compounds under mild conditions. In this work, the oxidative desulfurization performance over UiO-66(Zr) is greatly enhanced by Ti ion exchange. This strategy is not only efficient for UiO-66(Zr) with crystal defects but also for UiO-66(Zr) with high crystallinity. In particular, the performance of UiO-66(Zr) with high crystallinity in the oxidative desulfurization of dibenzothiophene can be improved more than 11-fold, which can be mainly attributed to the introduction of active Ti sites.

Hierarchization of Mordenite as NiW Sulfide Catalysts Support: Towards Efficient Hydrodesulfurization

NiW‐based catalysts were supported on Al2O3, commercial mordenite (HM), and hierarchical mordenite prepared by acid–base–acid treatment (HM–M). Their catalytic performance was evaluated in the hydrodesulfurization (HDS) of dibenzothiophene (DBT) and 4,6‐dimethyldibenzothiophene (4,6‐DMDBT) at 613 K under 4 MPa as total pressure. In the HDS of DBT, NiW/Al2O3 exhibited better catalytic activity than NiW/HM and NiW/HM–M. On the contrary, NiW/HM–M exhibited the highest catalytic performance in the HDS of 4,6‐DMDBT, attributed to different factors: an improved dispersion of the active phase, a better accessibility to the active sites owing to the creation of mesoporosity, and an additional reaction route (isomerization) owing to the acidic properties of the zeolitic support. These results show the potential interest of hierarchical mordenite as support for HDS catalysts, with the presence of mesoporosity beneficial to the HDS of large and refractory molecules.

Investigations on oil detachment from rough surfaces in an aqueous solution

Herein, detachment of oil molecules from perfect and defective aluminum oxide surfaces in an aqueous solution was investigated using atomistic molecular dynamics simulations. On the basis of the α-Al2O3 (0001) plane, three types of surface defects, pits, grooves, and protrusions, were created and applied to explore the effects of surface defects on the detachment of oil molecules in an aqueous solution. Our simulation results indicate that the surface defects with various topographies affected the oil detachment to different degrees. The adsorption conformation of oil molecules on each defective alumina surface evidently changed during the entire simulation. The effect of each type of surface defect on oil detachment follows the order grooves < pits < protrusions. After this, the oil–alumina and water–alumina interactions were investigated to determine the effects of the surface defects on the driving forces responsible for the conformational change of oil molecules on each type of defective alumina surface. The microscopic conformational changes and detachment of oil molecules from the defective alumina surface discussed herein are believed to be helpful to enrich the mechanism of oil detachment from a rough substrate surface.

A facile and green synthesis of MIL-100(Fe) with high-yield and its catalytic performance

MIL-100(Fe) is one of the important metal–organic frameworks due to its fascinating physicochemical properties. Generally, MIL-100(Fe) was synthesized under the conditions of adding HF and solvent. Here, we report that MIL-100(Fe) can be facilely synthesized without the addition of solvent and HF. More importantly, this approach can produce MIL-100(Fe) with a high yield of 93%. Additionally, the obtained MIL-100(Fe) exhibited good catalytic performance in the acetalization of benzaldehyde with methanol. This catalyst can still maintain the initial catalytic activity after five cycles.