Synthesis and Characterization of Metal-Supported Mesoporous Silicas Applied to the Adsorption of Benzothiophene

Abstract

ABSTRACT:The present work reports adsorption/desorption studies of benzothiophene (BT) onto SBA-15 loaded with Fe, Pd and Cu employing in situ FT-IR spectroscopy and batch liquid-phase adsorption methods. The adsorbents were prepared by post-synthesis impregnation of metal salts onto pure siliceous SBA-15 by solid mixture and incipient wetness methods. The adsorbents were characterized by nitrogen adsorption isotherms, TEM, X-ray diffraction and X-ray photoelectron spectroscopy (XPS). The incorporated metals, in different oxidation states, were dispersed as nanoparticles on the mesoporous channels of SBA-15. The surface area decreased significantly for samples with incorporated metals, especially for those prepared by solid-mixture impregnation (Cu and Pd), although the hexagonal arrangement and the average pore size remained virtually unaltered. As revealed by batch adsorption isotherms, the incorporation of metals effectively increased the retention of the adsorbent towards the sulphur compound in the following order: Pd > Fe > Cu. DRIFT spectra (under in situ adsorption/desorption conditions) of the samples containing Fe and Pd showed that adsorption of BT onto the former is mainly reversible, whereas BT seems to be chemisorbed in the latter and did not desorb readily upon thermal treatment under He flow.

Functionalization of SBA-15 with CeO2 nanoparticles for adsorptive desulfurization: Matters of template P123

“…Among the alternatives, one of the most important future directions of desulfurization is adsorption. There is great potential in using adsorbents for deep desulfurization, because organic sulfur molecules can be captured at ambient conditions with high efficiency (Song et al., 2014; Vilarrasa-Garcia et al., 2011b; Xiong et al., 2010). It is commonly known that both π complexation and direct sulfur metal (S–M) bonds can work for adsorptive desulfurization (Danmaliki and Saleh, 2017; Khan et al., 2017; Shi et al., 2017 Song et al., 2013).…”

“…Normally, the as-synthesized mesoporous silica is first to calcine, which leads to generate template-free mesoporous silica with open pores. The precursor is then incorporated into the open pores, with the second calcination to convert the precursor to active species (Cheng et al., 2015; Shao et al., 2012; Vilarrasa-Garcia et al., 2011b). This conventional method requires repeated calcination, which is low efficiency and energy consuming.…”

Synthesis and Application of Metal Doped Silica Particles for Adsorptive Desulphurization of Fuels

“…causes oligomerization of thiophenes leading to their removal from fuel stream at room temperature [41] as evidenced by appearance of -CH stretching vibrations at 2,800-2,900 cm -1 responsible for attachment of thiophene on silica binding sites [42]. These carbons result in bonding with metal adsorbent surface that lead to ring opening.…”

Benzothiophene adsorption on M/SBA‐15 and M/SBA‐15/NH4F modified (M = Fe or Co) in liquid phase batch system

“…Selective adsorption of thiophene‐derivative compounds is an alternative process to remove the last fraction of sulphur in fuels . Several porous solids such as activated carbons, SBA‐15, zeolites, and Al 2 O 3 have been reported as possible materials for this purpose. Incorporation of transition metals in these adsorbents has been employed to further improve their sulphur adsorption properties.…”

“…Several authors have carried out adsorption studies to remove sulphur species from liquid fuel. Vilarrasa‐García et al studied benzothiophene adsorption using different metals supported on a low‐cost porous silica (SBA‐15), using sodium silicate as a silicon precursor, which is more economically viable and displays lower toxicity than traditional alkoxides . The support was impregnated with different metals Pd (18.3 g/g), Fe (2 g/g), and Cu (28.8 g/g) and evaluated in batch experiments, showing sulphur adsorption capacities of 0.24 mmol/g for SBA‐15 (Pd), 0.23 mmol/g for SBA‐15 (Fe), and 0.21 mmol/g for SBA‐15 (Cu).…”