(544cs) Facile Fabrication of Dendritic Mesoporous Silica/Carbon Nanospheres for Selective Adsorptive Desulfurization

The combustion of sulfur compounds in commercial fuels emits large amounts of SOx, which is one of the main source of air pollution and makes seriously harm to people's health. Thus, the desulfurization of commercial fuels becomes an important worldwide issue. The heterocyclic sulfur compounds such as dibenzothiophene (DBT) and its derivatives are hard to be removed via Hydrodesulfurization (HDS) process due to the steric hindrance of alkyl substitutes, thus makes HDS process more complicated and inefficient. Therefore, the alternative desulfurization technologies to produce clean fuel with high efficiency and low energy consumption have been widely developed.

Adsorptive desulfurization (ADS) is recognized to be one of the most promising technology among alternative methods, as its apparent advantages of mild operating conditions, easy availability, hydrogen-free consumption, low cost, less environment pollution and so on. In the past decades, various types of adsorbents have been investigated. Among the materials, the mesoporous materials have received much attention owing to their unique physical and chemical properties, i.e. high surface area, large pore volume, ordered pore structure, good thermal and mechanical stabilities.

In this research, dendritic mesoporous silica/carbon nanospheres with various particle sizes and carbon contents were controllable facilely fabricated and applied in adsorptive desulfurization. Besides, a series of well-dispersed supported catalysts with the silver loading of 10 wt.% were prepared by wet impregnation and thermal dispersion. It was intriguing to find that the unique center-radial pore structure and large surface area (572 m²/g) of dendritic mesoporous silica/carbon nanospheres were favorable for the incorporation and good dispersion of active metals. The carbon substrate of samples could improve the adsorptive performance but was hostile for the dispersion of silver species. The adsorptive capacity could be significantly enhanced after the incorporation of AgNO₃, and also increased with the increase of carbon content. Generally, the adsorbent containing carbon species was prior to other samples for the selective adsorptive desulfurization. The adsorbent Ag/S-100-H₂SO₄ showed superior adsorptive performance with the highest activity (6.88 mg/g) and selectivity (4.84 mg/g) for DBT, which might result from a good combination of its large center–radial pore channels, the well dispersion/accessibility of active metals and a synergistic effect between carbon substrate and supported silver species. This research showed a promising material for Ï€-complexation adsorbent applied in selective adsorptive desulfurization.