Highly dispersive lanthanum oxide fabricated in confined space of SBA-15 for adsorptive desulfurization

Abstract

Lanthanum based adsorbents are promising in adsorptive desulfurization due to high activity. The dispersion degree of La2O3 impacts desulfurization performance directly, and the development of an efficient strategy for La2O3 dispersion still remained challenge. Herein, for the first time confined spaces and silanols of as-synthesized SBA-15 were used for dispersion of La2O3 over mesoporous silica. The La(NO3)3 precursor is directly introduced into the confined spaces between silica walls and template of as-synthesized SAB-15 by solid state dispersion (SSD) strategy. The SSD strategy assists the formation of small sized La2O3 with excellent dispersion after La precursor decomposition by the combined action of confined spaces and silanols. We also demonstrated that up to 20 wt% La2O3 can be highly dispersed over as-synthesized SBA-15 (LaAS-20). Our investigations show that well-dispersion of La2O3 correspond to high desulfurization activity for fuels, and the amount of thiophene captured can reach 0.12 mmol of S/g over LaAS-20, which is better than that over LaCS-20 and other La-doped reported sorbents. Furthermore, LaAS-20 adsorbent showed good stability and regeneration ability, and has potential applications to be applied in adsorptive desulfurization technology.