Size regulation and dispersion of ceria using confined spaces for adsorptive desulfurization

Transition-metal nanoparticles attracted tremendous attention in desulfurization technology because of their excellent sulfur adsorption activity. However, such activity is heavily relying on the size and dispersion degree of metal nanoparticles (NPs). Therefore, dispersion and regulation of NPs size is of significance importance. Herein, an efficient strategy is developed for the first time to regulate the size and highly disperse ceria NPs in a typical 3-D mesoporous silica KIT-6 by using silanols and confined spaces. The Ce-containing precursor is directly inserted into the confined spaces exist between template P123 and silica walls of as-prepared KIT-6 by solid-phase grinding. The subsequent calcination not only remove template from KIT-6 structure but also convert cerium precursor to CeO2 active sites in a single step, and hence avoided multiple calcination steps as reported in other strategies, and efficient in terms of time and energy. In contrast to reported strategies, the present approach is more convenient for synthesis of CeO2-based KIT-6 adsorbents. The synthesized materials (CeAK) were characterized via N-2 adsorption, XRD, TEM, SEM, elemental distribution mapping, FT-IR, TG, and UV-Vis DRS and compared with materials obtained from calcined KIT-6 (CeCK). Compared with CeCK sorbent, CeAK demonstrated smaller Ce particles and stronger interaction with silica support. As a result, it exhibited high thiophene adsorption capacity and can reach 0.14 mmol.g(-1) over CeAK-20, which is higher than that 0.07 mmol.g(-1) of CeCK-20. Furthermore, the desulfurization activity can be recovered well even after regeneration. Facile synthesis, high desulfurization activity, excellent stability and regeneration ability make the synthesized material highly attractive in deep desulfurization technology.