Catalysts Based on Acidic SBA-15 for Deep Oxidative Desulfurization of Model Fuels

Abstract

Acidic SBA-15 modified by molybdenum oxide has been synthesized. These materials were characterized by low nitrogen adsorption/desorption, Fourier transform infrared spectroscopy, transmission electron microscopy, NH3 temperature-programmed desorption, NMR, and XRD techniques. In this work, the activity of acidic Al-SBA-15 modified with molybdenum oxide in the oxidation of sulfur-containing compounds was investigated for the first time. It was shown that the SBA-15 support containing aluminum allows to significantly increase the catalytic activity of molybdenum oxide. The main factors affecting the process consisting of catalyst dosage, temperature, reaction time, oxidant dosage were investigated in detail. In the presence of synthesized catalysts, dibenzothiophene can be completely oxidized in 30 min. These catalysts retain their activity in DBT oxidation for 10 cycles.

Enthalpies of Immersion in Caffeine and Glyphosate Aqueous Solutions of SBA-15 and Amino-Functionalized SBA-15

“… 12 Additionally, the ability of SBA-15 to host a large series of functional groups by methods of cocondensation, isomorphic replacement, or grafting leads it to be a promising porous solid 10 that opens a tremendously valuable possibility of developing solids with very specific characteristics, for industrial applications related to adsorption processes 16 , 17 and membrane separation, 18 , 19 in pharmaceutical applications like drug delivery, 20 , 21 biosensing, 22 , 23 and for catalysis. 24 , 25 …”

Nanocatalysts for Oxidative Desulfurization of Liquid Fuel: Modern Solutions and the Perspectives of Application in Hybrid Chemical-Biocatalytic Processes

“…In recent years many strategies have been developed to immobilize homogenous POMs in various supports to form new catalytically active and easily recoverable materials (Tables 1 and 2 [16,60], mesoporous mesostructured silicates (MCM-41, SBA-15, etc.) [69], natural microporous materials (such as zeolites, bentonites, montmorillonite (MMT), etc. ), polymeric organic supports (poly(vinyl alcohol) (PVA), chitosan (CS), etc.…”

“…This layer can increase the efficiency of the catalyst's attachment to the support [77]. In contrast to MCM-41, SBA-15 has a higher pore size and stronger pore walls, which explains the preference given to SBA-15 by many researchers when developing NCs [69,78].…”

“…According to the literature, the efficiency of the oxidative activity of the NCs depends on the amount of electron density of the sulfur atom and the spatial structure of the sulfur-containing compound [69]. The reactivity of substrates increases along with the electron density of the sulfur atom.…”

“…The efficiency of Mo/Al-SBA15 as an NC for ODS changed in the series starting with DBT and decreasing for the derivatives with lower electron density or greater steric hindrances: 4methyl phenyl sulfide (MeSPh) > dibenzyl sulfide (Bn 2 S) = DBT > 4,6-dimethylDBT (Me 2 DBT) > methylDBT (MeDBT) > benzothiophene (BT) > 5-methylbenzothiophene (MeBT) [69]. The desulfurization efficiency of most of the known NCs for ODS was found to decrease in the series: DBT > BT > thiophene (TH) (Tables 1 and 2), whereas the trend for hydrodesulfurization (HDS) was exactly reversed: THs > BTs > DBTs [18].…”