Study on the preparation of amine-modified silicate MCM-41 adsorbent and its H₂S removal performance

Abstract

A series of APTMS ((3-aminopropyl)trimethoxysilane)-modified silicate MCM-41 adsorbents ( x-APTMS/MCM-41, x is the volume of APTMS per 1 g of silicate MCM-41) with different APTMS contents was prepared, and the effects of APTMS content on the desulfurization performance of the APTMS/MCM-41 adsorbents were studied in a fixed adsorption bed using H2S and N2 mixture as a model gas. The as-prepared adsorbents were characterized by X-ray diffraction analysis, N2 adsorption–desorption, Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, and energy-dispersive spectroscopy. The results showed that all the APTMS-modified x-APTMS/MCM-41 adsorbents retained the mesoporous silica structure of MCM-41. The Brunauer–Emmett–Teller-specific surface area of x-APTMS/MCM-41 increased slightly with increasing x at first and then decreased with further increasing APTMS content. The H2S removal performances of x-APTMS/MCM-41 adsorbents decreased in the order 0.6-APTMS/MCM-41 > 0.7-APTMS/MCM-41 > 0.5-APTMS/MCM-41 > 0.4-APTMS/MCM-41 > 0.8-APTMS/MCM-41. At x = 0.6, the maximum H2S removal rate of 54.2% and H2S saturated capacity of 134.4 mg g−1 were observed. The regeneration experiment of 0.6-APTMS/MCM-41 adsorbent after three times regeneration at 423 K for 3 h in nitrogen confirmed that it possessed a good regenerability.

Synthesis of Rice Husk-Based MCM-41 for Removal of Aflatoxin B1 from Peanut Oil

“…MCM-41 has been used in many applications in the fields of catalysis, adsorption, separation, chromatography, and others. Moreover, MCM-41 and its modified products exhibited a broad-spectrum capacity to adsorb many types of adsorbates, such as metal ions, dyes, gases, and drugs [16][17][18][19]. In addition, as-synthesized and modified MCM-41 exhibited good adsorption performance for organic compounds, particularly aromatic compounds such as benzene [20], mesitylene [21], phenol [22], toluene [23], aniline [24], and chlorophenol [25].…”

Removal of Hexamethyldisiloxane via a Novel Hydrophobic (3–Aminopropyl)Trimethoxysilane-Modified Activated Porous Carbon

“…In Figure 2 e, the FTIR investigations of APC and APTMS@APC–0.125 are shown. The broad band at 3441 cm −1 is the characteristic absorption peak of –OH, corresponding to the dense surface hydroxyl group and adsorbed H 2 O molecules [ 34 , 35 ]. However, the band at 3441 cm −1 in the spectra of APC is apparently stronger than that of APTMS@APC–0.125, suggesting that the former could be more hydrophilic.…”

“…The peak at 1174 cm −1 for APC belongs to C–O–C stretching vibrations [ 14 , 30 , 31 ]. The peak at 1629 cm −1 for APC is attributed to –OH bending [ 35 ], while 1622 cm −1 for APTMS@APC–0.125 is assigned to –OH or –NH 2 bending [ 36 ]. In addition, the peaks at 2930 and 2865 cm −1 for APTMS@APC–0.125 are attributed to the C–H stretching vibrations of –CH 3 and –CH 2 – [ 35 ]; those at 1128 and 1025 cm −1 can be corresponded to the C–O stretching vibrations and Si–O bond asymmetric stretching vibrations [ 36 , 37 ]; a peak at 775 cm −1 is related to Si–C bond stretching vibrations [ 38 ]; and a peak at 686 cm −1 is assigned to the N–H bending vibration [ 35 ].…”

“…These results indicate that water can lead to the hydrolysis of APTMS molecules during the silylation reaction, thus condensing with the already present hydroxyl group. APTMS can be bonded to the APC surface by one, two, or three bridged hydroxyl groups depending on the density of –OH groups on the APC surface [ 35 , 42 ]. Also, the bands of –OCH 3 , Si–O, and –NH 2 are evident in the FTIR spectra ( Figure 2 e).…”

“…It can be no porosity of APC and APTMS@APC−0.125 was observed. After APTMS coating obvious increase in the density of spherical particles on the APTMS@APC−0.1 In Figure 2e, the FTIR investigations of APC and APTMS@APC−0.125 are broad band at 3441 cm −1 is the characteristic absorption peak of −OH, corres the dense surface hydroxyl group and adsorbed H2O molecules [34,35]. Ho…”