SignificanceA novel approach for ultra-deep desulfurization of diesel fuel was proposed, in which the original fuel was treated by light-irradiation before adsorptive desulfurization (ADS) over the TiO 2 -CeO 2 /MCM-48 adsorbent under ambient conditions. A superior capacity of 95 cm 3 -fuel/g-adsorbent (32 times higher than that of the original fuel) was achieved. The promoting effect of light-irradiation was likely through in-situ peroxides generation in fuel under visible light/sunlight, which may oxidize organosulfur to form strongly adsorbed sulfones over the adsorbent.

This study investigates ultra-deep adsorptive desulfurization (ADS) from light-irradiated diesel fuel over supported TiO2–CeO2 adsorbents. A 30-fold higher desulfurization capacity of 95 mL of fuel per gram of adsorbent (mL-F/g-sorb) or 1.143 mg of sulfur per gram of adsorbent (mg-S/g-sorb) was achieved from light-irradiated fuel over the original low-sulfur fuel containing about 15 ppm by weight (ppmw) of sulfur. The sulfur species on spent TiO2–CeO2/MCM-48 adsorbent was identified by sulfur K-edge XANES as sulfones and the adsorption selectivity to different compounds tested in a model fuel decreases in the order of indole > dibenzothiophenesulfone ≫ dibenzothiophene > 4-methyldibenzothiophene > benzothiophene > 4,6-dimethyldibenzothiophene > phenanthrene > 2-methylnaphthalene ∼ fluorene > naphthalene. The results suggest that during ADS of light-irradiated fuel, the original sulfur species were chemically transformed to sulfones, resulting in the significant increase in desulfurization capacity. For different supports for TiO2–CeO2 oxides, the ADS capacity increases with a decrease in the point of zero charge (PZC) value; for silica-supported TiO2–CeO2 oxides (the lowest PZC value of 2–4) with different surface areas, the ADS capacity increases monotonically with increasing surface area. The supported TiO2–CeO2/MCM-48 adsorbent can be regenerated using oxidative air treatment. The present study provides an attractive new path to achieve ultraclean fuel more effectively.

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in Wiley Online Library (wileyonlinelibrary.com) Air-promoted adsorptive desulfurization (ADS) of commercial diesel fuel over a Ti-Ce mixed oxide adsorbent in a flow system is investigated in this work. The fresh/spent adsorbents were characterized using X-ray absorption near edge structure spectroscopy. Results show that sulfoxide species are formed during air-promoted ADS over Ti 0.9 Ce 0.1 O 2 adsorbent. Adsorption selectivity of various compounds in fuel follows the order of dibenzothiophene sulfone > dibenzothiophene ' benzothiophene > 4-methyldibenzothiophene > 4,6-dimethyldibenzothiophene > phenanthrene > methylnaphthalene > fluorene > naphthalene. The high adsorption affinity of sulfoxide/sulfone is attributed to stronger Ti-OSR 2 than Ti-SR 2 interactions, resulting in significantly enhanced ADS capacity. Adsorption affinity was calculated using ab initio methods. For Ti-Ce mixed oxides, reduced surface sites lead to O-vacancy sites for O 2 activation for oxidizing thiophenic species. Low temperature is preferred for air-promoted ADS, and the Ti-Ce adsorbent can be regenerated via oxidative air treatment. This study paves a new path of designing regenerable adsorbents.

Here we report a new approach to enhance CO 2 capture and separation over a solid molecular basket sorbent by reorganizing the aggregation of fumed silica (FS) support particles with the addition of 3-aminopropyltriethoxysilane (APTES). After APTES modification, although the surface area of fumed silica decreased, the total pore volume increased significantly, more than 2 times larger than that of fumed silica itself. Compared to fumed silica supported PEI sorbent, the 30PEI/APTES-FS sorbent can achieve a CO 2 capacity as high as 130.4 mg-CO 2 /g-sorb, a 44% increase from 90.4 mg-CO 2 /g-sorb over 30PEI/FS. The amine efficiency of PEI for CO 2 sorption was also improved by over 25%. Furthermore, both the CO 2 sorption and desorption kinetics were greatly enhanced by 1.23 and 1.61 times, respectively, compared to the PEI/FS sorbent without APTES modification. In addition, the stability and regenerability of PEI/FS sorbent was also greatly improved.