Ionic liquid-supported 3DOM silica for efficient heterogeneous oxidative desulfurization

Abstract

DBT is absorbed by IL-3DOM SiO2 and then oxidized to DBTO2 in the presence of H2O2.

Recent Advances in Functionalized Mesoporous Silica Frameworks for Efficient Desulfurization of Fuels

“…In a typical ODS process, oxidation of heavy sulfides takes place by incorporation of oxygen atoms at sulfur sites, without rupturing C–S bonds in the presence of judiciously selected oxidants, such as H 2 O 2 , O 3 , NO 2 , peroxy salts, or tertbutyl-H 2 O 2 . Out of these, H 2 O 2 is the most widely used oxidant; however, in recent years, transition metal-based oxidizing agents (Re, Mo/W oxides, tungstophosphoric acid, MPcS and persulfates, tetra-amido macrocyclic ligands) have become popular and have been investigated in combination with hydrogen peroxide [ 57 , 58 , 59 , 60 ]. The success of an ODS process depends on the textural, structural, surface, and chemical properties of an active catalyst, combined with an appropriate oxidant.…”

“…This enhanced performance can be attributed to the larger mesoporous specific surface area, peculiar hierarchically meso/macrochannels structural characteristics and shorter length of mesoporous channels that facilitate mass transfer of precursors and products. Recently, Chen et al reported on a POM-based ionic liquid supported 3DOM silica (IL-3DOM SiO 2 ) as a catalyst for heterogeneous oxidative desulfurization [ 58 ]. The catalyst exhibited high porosity, as well as, a high specific surface area.…”

“…The desulfurization performance of IL-3DOM SiO 2 catalyst decreased in the following order: 4-MDBT > DBT > 4,6-DMDBT > 3-MBT > BT. Additionally, even after recycling 17 times, the sulfur removal efficiency could still reach 94% in the absence of a regeneration process [ 58 ]. The mechanism of DBT desulfurization by IL-3DOM SiO 2 is shown to proceed, firstly via adsorption of DBT in the macropores and then its reaction with peroxo species formed in turn from the combination of POM-IL with H 2 O 2 .…”

“…In comparison to polyoxometalates (POMs), Keggin-type heteropolyacids (HPAs) have shown high catalytic activity for oxidation studies, owing to their high chemical resistance and mechanical robustness, making them suitable for desulfurization reactions as mentioned earlier, when they were combined with meso/macroporous silica [ 58 ]. Heteropolyacids have octahedral MO 6 units, and their lowest unoccupied molecular orbitals (LUMO) are mainly the non-bonding metal orbitals, allowing easy participation in redox reactions [ 134 , 135 ].…”

Atomic layer deposition of nano-scale molybdenum sulfide within a metal–organic framework for highly efficient hydrodesulfurization

“…Over the years, the burning of sulfur compounds has accelerated environmental degradation and had a serious impact on human life. 1,2 Desulfurization has become one of the major problems for the petroleum industry, especially in the context of strict legislation and increasing environmental awareness. 3 In China, the United States and other countries and regions, the sulfur content in fuel is strictly limited to less than 10 mg g À1 .…”