Desulfurization Reaction Research Articles

Hydrothermal desulfurization of spent lead paste based on comproportionation reaction

A hydrothermal method was adopted to strengthen the desulfurization reaction of PbSO4 with the aim of addressing the problem of incomplete desulfurization and large reagent consumption in the pretreatment process of spent lead paste. Mineral liberation analysis showed that lead sulfate disseminates in lead oxide and they become mixed with each other, which is an important reason for incomplete desulfurization via conventional methods. E-pH diagrams of the Pb-SO42-–H2O system at different temperatures indicate that the pH value of PbSO4 converted to PbO decreased with an increase in temperature. Experimental results showed that increases in time, the NaOH excess coefficient, temperature, stirring rate, and the liquid-solid ratio are beneficial for improving the desulfurization ratio. Under hydrothermal conditions, PbO and PbO2 react to form Pb3O4, and this comproportionation reaction destroys the encapsulation of the solid product layer and is conducive to the progress of the desulfurization reaction. Under the optimized reduction conditions (i.e., time of 60 min, sodium hydroxide coefficient of 1.1, temperature of 150 °C, liquid-solid ratio of 10 mL/g, and stirring rate of 600 rpm), a 98.95% desulfurization ratio was achieved. The phases of lead in the desulfurization residue were mainly PbO, PbO2, and Pb3O4, and these can be recovered via low-temperature reduction smelting.

Ligand Modified Metal Organic Framework UiO-66: A Highly Efficient and Stable Catalyst for Oxidative Desulfurization

It is reported that the UiO-66(Zr) material could catalyze oxidative desulfurization (ODS) reaction, but its stability is inferior. In this work, a family of functionalized UiO-66(Zr) with different groups (–NH2, –NO2, –Br) were prepared to enhance this material’s activity and stability. Characterizations and ODS tests show that the groups have profound influence over the physicochemical properties of UiO-66(Zr). Among functionalized UiO-66(Zr), UiO-66(Zr)-NO2 exhibited the best ODS activity, their ODS performance is linear correction with their Hammett values. Recycling experiments indicate UiO-66(Zr)-NO2 has no deactivation.

A comparative evaluation of recarbonated CaCO3 derived from limestone under oxy-fuel circulating fluidized bed conditions

SO2 emissions from coal-fired boilers are air pollutants and a source of acid rain, causing extensive environmental pollution. Limestone (CaCO3) is a Ca-based sorbent which is injected into circulating fluidized bed (CFB) boilers, where it combines with SO2 to produce calcium sulfate (CaSO4). As a result, SO2 emissions from a power plant are reduced. In this study, CaCO3 addition was proposed and the desulfurization efficiency improved. The direct desulfurization reaction is dominant in a commercial CFB boiler due to the high CO2 partial pressure, but CaO is formed at a fast reaction rate by calcination in the high temperature or in the low CO2 partial pressure region. When CaO remains in the loop seal, it is exposed to a high CO2 partial pressure condition moving through the recirculation section for an extended period and re-injected into the furnace as recarbonated CaCO3. To analyze the direct desulfurization reaction kinetics, a shrink core model in which the reaction proceeds inside the particle was adopted. Surface observations through FE-SEM of CaSO4 produced by the 180 minute long desulfurization experiment using TGA suggest that the CaSO4 crystal growth rate increased after the pre-treatment (recarbonation) of limestone. Recarbonation lowered the limestone crystallinity, causing a faster reaction. The CaCO3 recarbonation increased the Ca utilization by more than 20% when the direct desulfurization reaction occurred. The TGA experiments show that recarbonation contributes to CaSO4 conversion. Increasing the desulfurization efficiency using recarbonation can reduce the fixed investment and operating costs of oxy-fuel CFB plants because only desulfurization in the furnace is able to meet SO2 emission regulations or lower the flue gas desulfurization (FGD) dependence. Accordingly, the desulfurization conversions of recarbonated CaCO3 and limestone were compared in this study. Morphological changes in the limestone were also evaluated using XRD, FE-SEM, and other analysis methods.

Structural Evidence for a [4Fe‐5S] Intermediate in the Non‐Redox Desulfuration of Thiouracil

AbstractWe recently discovered a [Fe‐S]‐containing protein with in vivo thiouracil desulfidase activity, dubbed TudS. The crystal structure of TudS refined at 1.5 Å resolution is reported; it harbors a [4Fe‐4S] cluster bound by three cysteines only. Incubation of TudS crystals with 4‐thiouracil trapped the cluster with a hydrosulfide ligand bound to the fourth non‐protein‐bonded iron, as established by the sulfur anomalous signal. This indicates that a [4Fe‐5S] state of the cluster is a catalytic intermediate in the desulfuration reaction. Structural data and site‐directed mutagenesis indicate that a water molecule is located next to the hydrosulfide ligand and to two catalytically important residues, Ser101 and Glu45. This information, together with modeling studies allow us to propose a mechanism for the unprecedented non‐redox enzymatic desulfuration of thiouracil, in which a [4Fe‐4S] cluster binds and activates the sulfur atom of the substrate.

Structural Evidence for a [4Fe-5S] Intermediate in the Non-Redox Desulfuration of Thiouracil.

We recently discovered a [Fe-S]-containing protein with in vivo thiouracil desulfidase activity, dubbed TudS. The crystal structure of TudS refined at 1.5 Å resolution is reported; it harbors a [4Fe-4S] cluster bound by three cysteines only. Incubation of TudS crystals with 4-thiouracil trapped the cluster with a hydrosulfide ligand bound to the fourth non-protein-bonded iron, as established by the sulfur anomalous signal. This indicates that a [4Fe-5S] state of the cluster is a catalytic intermediate in the desulfuration reaction. Structural data and site-directed mutagenesis indicate that a water molecule is located next to the hydrosulfide ligand and to two catalytically important residues, Ser101 and Glu45. This information, together with modeling studies allow us to propose a mechanism for the unprecedented non-redox enzymatic desulfuration of thiouracil, in which a [4Fe-4S] cluster binds and activates the sulfur atom of the substrate.

Progress in organic fluorescent probes for detecting metal ions in environment

The massive emission of various pollutants leads to severe environmental problems, and the air and water issues attract enormous attention. Heavy metal ions highly affect our life and may cause many diseases, which is a critical issue to be solved. As reported, copper ion is highly related to some neurodegenerative diseases, such as Menkes and Wilson’s diseases. Children are susceptible to mercury ion during the early stages of development, leading to a variety of diseases relating to the brain, kidney and central nervous system. Thus, it is of vital importance to develop facile and fast detection methods for life-threatening metal ions. Organic dyes with various functional groups have shown great potential for detecting various metal ion pollutants through apparent color and fluorescence changes, exhibiting excellent selectivity and sensitivity. In terms of photophysical properties and chemical structures of organic dyes, we summarize recent research progress of the commonly seen detection mechanisms for metal ions. The detection mechanisms include photoinduced electron transfer (PET), intramolecular charge transfer (ICT), fluorescence resonance energy transfer (FRET), through-bond energy transfer (TBET), aggregation-disaggregation effect and rearrangement of molecular structures. As one of the mostly studied mechanisms, PET has been widely used in the construction of metal ion probes. These metal ion probes generally consist of three parts including fluorophores, spacers, and recognition sites. Most probes based on the PET mechanism are easily designed with high sensitivity and selectivity. However, most of these probes have no built-in correction, resulting in severe external environment interference. Compared with the PET mechanism, ICT mechanism has great superiority for the construction of ratiometric probes with built-in correction, which can minimize external interference and make quantitative detection more reliable. In addition, ICT mechanism provides another way for detecting some electron-donating and electron-accepting metal ions, such as Fe2+, Cu2+ and Zn2+. To achieve FRET within the probe, fluorophores are usually linked by a nonconjugated spacer, and the energy transfers from the donor to acceptor. In this scenario, spectral overlap is required. On the contrary, in TBET-based fluorescent chemosensors, a rigid conjugated linker is needed to chemically connect fluorophores and thus spectral overlap is not required. However, most of the reported FRET and TBET chemosenmsors are based on rhodamine dyes. It is highly necessary to develop novel energy transfer systems for expanding the variousness of metal ions probes. Naked-eye detection is the one of the most convenient methods for environmental metal ion sensing. Modulating the π-conjugated system of probes result in huge absorption spectrum change and lead to apparent color change of the probe, which is a promising strategy for developing naked-eye metal ions probes with high contrast. Moreover, mechanisms with aggregation-induced signal change including aggregation-caused quenching (ACQ) and aggregation-induced emission (AIE) are studied for environmental pollutant metal ion detection. Above all, these sensing strategies guarantee the successful development of metal ion probes. In this review, the basic design principles and responding mechanisms of the metal ion probes are discussed. Most of the probes can chelate with metal ions and some special reactions between probes and metal ions are also introduced including desulfurization reaction, redox reaction and Heck reaction etc. At last, the developing trends and the prospects of metal ion probes are presented.

Synergistic Effect between Zr-MOF and Phosphomolybdic Acid with the Promotion of TiF4 Template.

Metal-Organic Framework (MOF) materials are often modified or functionalized, and then the crystal size and morphology of MOF materials are changed. In the process of preparing UiO-66 confined phosphomolybdic acid (PMA) composites (PU), the TiF4-modified PU (PMA + UiO-66) composite catalyst (TiF4-PU) was successfully synthesized by adding titanium tetrafluoride, and the catalytic desulfurization activity was excellent. Similarly, the reaction mechanism was investigated by means of infrared spectroscopy, Raman spectroscopy, XPS, and UV/Vis spectroscopy. The results show that the addition of TiF4 not only changes the appearance and color of the catalyst, but also changes the valence distribution of the elements in the catalyst. The number of oxygen vacancies in the MOF increases due to the addition of TiF4, and more electrons are transferred from the Zr-MOF to PMA to form more Mo5+, which improved the performance of oxidative desulfurization in comparison. Thus, a stronger strong metal-support interaction (SMSI) effect is observed for TiF4-modified PU catalysts. In addition, the quenching experiment of free radicals shows that ·OH radical is the main active substance in the oxidative desulfurization reaction over TiF4-PU catalyst.

Study on the removal of thiophene sulfides by porous core-shell SiO2 @Cu/Ni

Porous SiO2@Cu/Ni core-shell nanomaterials were prepared by the sol-gel method. The results of HADDF-STEM and XRD indicated that Cu and Ni were evenly distributed on the surface of the SiO2 supporter. XPS and H2-TPR showed that the chemical state of Cu and Ni were conducive to the desulfurization reaction. The catalytic performance of samples was evaluated through the desulfurization ratios using 4, 6-Dimethyldibenzothiophene as the model sulfide. The effect of metal loading, Ni:Cu ratios, and temperature on the desulfurization, the selectivity of sulfone and 3-3′-dimethylbiphenyl was investigated. The results suggested that the desulfurization activities of 20 wt % SiO2@Cu/Ni were much higher than those of the other catalysts. Due to the synergistic effect among Cu, Ni, and the supporter, the desulfurization rate and selectivity of sulfone and 3-3′-dimethylbiphenyl were all 100% under the suitable conditions. And after the reaction, ICP-OES results showed that the catalyst composition was unchanged, indicating that SiO2@Cu/Ni had good stability while maintaining excellent catalytic performance. Also, the desulfurization mechanism of SiO2@Cu/Ni core-shell nanomaterials was proposed in the present work.

A Nanosized Propeller-like Polyoxometalate-linked Copper(I)-Resorcin[4]arene for Efficient Catalysis.

The design and assembly of polyoxometalate-resorcin[4]arene-based metal-organic molecular materials are particularly attractive for their elegant structures and potential functions. By applying a newly designed resorcin[4]arene ligand (TPC4R-II), a copper(I)-coordinated polyoxometalate-based metal-organic molecular material, namely, [CuI6(Br)3(TPC4R-II)3(PMo12O40)]·8H2O (1), was rationally assembled. Three copper(I)-coordinated resorcin[4]arenes are held together by a central [PMo12O40]3- to yield a supramolecular propeller. 1 features efficient catalytic performances for oxidation desulfurization (ODS) and azide-alkyne cycloaddition (AAC) reactions. This work affords a feasible method for the nanosized polyoxometalate-based metal-resorcin[4]arene assemblies by well combinating two types of large composites as well as low coordination metal cations.

Titanium-Modified MIL-101(Cr) Derived Titanium-Chromium-Oxide as Highly Efficient Oxidative Desulfurization Catalyst

A titanium-chromium-oxide catalyst was prepared by a facile calcination of titanium-modified MIL-101(Cr). The resulting material, possessing a surface area of 60 m2 g−1 and a titania content of 50.0 wt%, can be directly used as the catalyst for oxidative desulfurization (ODS) reaction of dibenzothiophene (DBT). This novel ODS catalyst can remove 900 ppm sulfur-containing compounds in a reaction time of 30 min at 60 °C. The experimental results showed that the specific activity increased with the titanium content. The specific activity of the catalyst with 50%Ti reached 129 μmol/m2, which was much higher than that of reported Ti-based catalysts.

Creation of Hierarchical Titanosilicate TS‐1 Zeolites

AbstractHierarchical TS‐1 zeolites that possess at least two levels of porosities have aroused growing interest in the past years. The enhanced mass transfer efficiency and increased accessibility of Ti active sites in the hierarchical TS‐1 zeolites greatly improve the catalytic performance by overcoming the steric and diffusional problems. In this review, recent important progress in the construction of hierarchical TS‐1 zeolites is presented, including mesoporogen, mesoporogen‐free, and demetallization strategies. Effective characterization methods for the Ti species and the hierarchical zeolite structures are described. The impacts of hierarchical structures on the creation of active Ti species and improvement of catalytic performances in the oxidative desulfurization and epoxidation reactions are highlighted. Finally, current challenges and future development perspectives for preparing hierarchical TS‐1 zeolite catalysts are addressed.

Two-dimensional CaO/carbon heterostructures with unprecedented catalytic performance in room-temperature H2S oxidization

Two-dimensional (2D) carbon-based materials are attracting increasing interest as promising desulfurizers for tackling H2S emission issues at room temperature. Herein, the 2D CaO/carbon heterostructures are synthesized by a one-step method for H2S catalytic oxidation. Results indicate that the catalysts exhibit robust catalytic H2S performance with significant promotions for the generation of active oxygen species and the dissociation of H2S. Moreover, the roomy and open space created by 2D nanosheet structure could offer more exposed active sites for desulfurization reaction and larger storehouse for sulfur products compared with porous carbons. Consequently, the breakthrough sulfur capacity of the 2D CaO/carbon heterostructures achieves an unprecedented value of 9.10 g/g. Furthermore, a possible mechanism of H2S catalytic oxidation on the catalysts is proposed based on the experimental and characteristic results. This work could shed lights on the facile fabrication of high-capacity catalysts for H2S oxidation and the desulfurization behavior of the 2D carbon-based materials.

Study on Preparation Method of Terminal Blend Rubberized Asphalt Binder

Terminal Blend rubberized asphalt binder is generally prepared under high temperature conditions. Unlike asphalt plants that produce asphalt in sealed asphalt tanks, the process of laboratory interaction of asphalt and crumb rubber is mostly in contact with air, which can easily cause asphalt aging. To alleviate this phenomenon, TB-B and TB-C asphalt were prepared using crumb rubber in a nitrogen environment and soluble crumb rubber in an atmospheric environment, respectively.As a comparison group, TB-A asphalt was prepared using crumb rubber under atmospheric environment. A practical method for preparing TB asphalt was explored by changing the amount of crumb rubber and the interaction temperature. Their rheological characteristics were measured by dynamic mechanical methods using dynamic shear rheometer (DSR) and binding beam rheometer (BBR). It was found that under high interaction conditions, the crumb rubber in TB-A asphalt undergoes desulfurization and degradation reactions, which caused the hinge structure in the asphalt to be damaged and the high-temperature performance decreased. But the aliphatic compounds generated by the degradation of crumb rubber are beneficial to improve the low temperature performance of asphalt. Through polymer isolation experiments, it was found that the degradation of crumb rubber caused TB-A and TB-B asphalt to form a homogeneous system. While the soluble crumb rubber in TB-C asphalt was mainly swelling reaction, so the larger the amount of soluble crumb rubber, the more severe the segregation. Besides, the aging degree of three TB asphalts was studied by using viscosity experiments, thermal analysis and Fourier transform infrared (FT-IR) spectroscopy. The results show that compared with TB-A asphalt, the aging degree of TB-B and TB-C asphalt is greatly reduced. Therefore, both preparation methods effectively alleviate the aging phenomenon in the laboratory preparation of TB asphalt.

Macroporous 3D carbon-nitrogen (CN) confined MoOx catalyst for enhanced oxidative desulfurization of dibenzothiophene

Macroporous 3D carbon doped with nitrogen confined Mo catalyst (MoOx@CN) had been prepared by a facile one-step pyrolysis technique using silica as a template and was employed for oxidative desulfurization (ODS) of dibenzothiophene (DBT) in model fuel with H2O2 as oxidant. The effect of different operating conditions (i.e., reaction temperature and time, catalyst dosage, H2O2/DBT (O/S) molar ratio) were also systematic investigated. Under the optimal reaction condition, MoOx@CN catalyst exhibited highly excellent ODS performance toward DBT, the highest sulfur removal efficiency can be up to 99.9% and sulfur content was wiped out from 800 ppm to 10 ppm. Due to the robust 3D structure promoting rapid transfer, in addition to the increased number of active sites induced by the Mo vacancies, the catalyst, prepared using chitosan and ammonium heptamolybdate in a mass ratio of 1:0.5, displayed rapid kinetics and low activation energy in the oxidation of dibenzothiophene. Moreover, it exhibited excellent recyclability after five cycles without any obvious decrease in catalytic activity for the oxidative desulfurization reaction.

A dual thiourea-appended perylenebisimide “turn-on” fluorescent chemosensor with high selectivity and sensitivity for Hg2+ in living cells

Sensing heavy metal ions particularly for the most toxic Hg2+ is a long-term pursuit for chemists because of its obvious and extreme harmfulness to both the environment and human health. Herein, a novel 'turn-on' perylenebisimide-thiourea fluorescent probe PBI-BTB is achieved for rapid detection of Hg2+ in a DMSO/H2O (5/1, v/v) solution through a typical Hg2+-promoting desulfurization reaction, which has been investigated through Job's plot titration, FT-IR, 1H NMR and HRMS analysis. A remarkable fluorescence emission enhancement at 540 and 580nm is observed in the presence of Hg2+, which is visible to the naked eye with high selectivity and sensitivity. Moreover, probe PBI-BTB combined strong anti-interference recognition with short response time (< 1min). The rapid fluorescence response with low limit of detection (0.35μM) in a wide pH range of 3.0-11.0 makes PBI-BTB a promising candidate for detection of Hg2+ without any buffer system. Furthermore, the practicability of probe PBI-BTB upon the Hg2+ recognition in human liver cancer cells (HepG-2) has been studied through fluorescent live cell imaging which reveals the probe's low toxicity to organism as well as the favorable cell permeability of PBI-BTB for detecting Hg2+ in biological systems.

Mechanistic insights into sulfur rich oil formation, relevant to geological carbon storage routes. A study using (+) APPI FTICR-MS analysis

Sulfur incorporation into sedimentary organic matter has a key role in carbon preservation in the geosphere. Such processes can inform strategies for human timescale carbon storage to mitigate climate change impacts and thus more detailed knowledge of sulfur incorporation into biomass species is needed. Until recently, detailed chemical characterization of sulfurized organic matter was only possible by analyzing individual building blocks obtained after desulfurization reactions. In this study, Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS), with atmospheric pressure photoionization in positive ion mode, (+) APPI, was used to investigate the chemical composition of sulfur rich crude oils and to obtain mechanistic insights into the sulfur incorporation reactions happening during early diagenesis. Contrary to expectations, (+) APPI FTICR-MS data show that sulfurized lipids (with up to 6 sulfur atoms and up to m/z 1100) occur as free molecules in these oils, rather than within a macromolecular network linked by (poly)sulfide bridges. In contrast to the mature Peace River (Canada) oils, the thermally immature Rozel Point (USA) and Jianghan Basin (China) oils show a carbon number preference in sulfurized species resembling biogenic precursor molecules, which highlights the importance of S-bound molecules as geochemical proxies for early diagenetic processes. This study indicates that sulfur incorporation reactions involve the formation of S-cyclic structures in which the double bond equivalent is ≥ the number of S atoms. Collision induced dissociation (CID-) FTICR-MS experiments suggest the occurrence of intermolecular sulfur incorporation reactions, but only as a mechanism that is secondary to intramolecular sulfur addition. The CID-FTICR-MS experiments indicated that steroid sulfurization typically yields S-bearing cyclic structures and that thiol/thioether groups may be present throughout the chemical matrix but only to a minor extent. In addition, CID-FTICR-MS also confirms the occurrence of sulfurized alkenones in low maturity oils. Knowledge of organic sulfur molecule formation informs routes for carbon dioxide removal technologies that could be used to sequester carbon in the geosphere and/or hydrosphere in the form of recalcitrant organic species.

A study of the desulfurization selectivity of a reductive and extractive desulfurization process with sodium borohydride in polyethylene glycol

The selectivity of a facile reductive and extractive desulfurization process was studied. In this desulfurization method, polyethylene glycol was used as the extractant, and sodium borohydride was used as the reductant. Several different simulated fuels were prepared by dissolving thiophenic sulfides, methylbenzene and hexylene in octane. The results showed that methylbenzene and olefins had different effects on different sulfur compounds during this desulfurization process. The extraction and reduction mechanisms were also explained. Four factors could affect the desulfurization performance: (1) intermolecular hydrogen bonding: (a) active O bonding with aromatic H or (b) S bonding with H atoms in hydroxide radicals, (2) “like-dissolves-like” interactions between polyethylene glycol and thiophenic sulfides, (3) the methyl steric hindrance effect and the electron density of sulfur atoms, and (4) the combination of S atoms with produced nickel boride to form active desulfurization centres. The desulfurization reaction path was also deduced according to the GC/MS results.

A thiourea-based fluorescent chemosensor for bioimaging hypochlorite

A thiourea-based fluorescent turn-off chemosensor FHC was developed for recognizing hypochlorite. With the addition of hypochlorite to FHC, FHC displayed a specific desulfurization reaction of the thiourea group followed by the fluorescent quenching response. The fluorescent turn-off response of FHC to hypochlorite was very fast to finish within a few seconds. Detection limit of hypochlorite was determined to be 0.43μM. FHC can be applied for the bioimaging of hypochlorite in both HeLa cells and zebrafish. Response process of FHC to hypochlorite, via the desulfurization of the thiourea moiety, was demonstrated, based on 1H NMR titrations, ESI-mass, fluorescent and UV–vis titrations and DFT calculations.

The synthetic strategies of hierarchical TS-1 zeolites for the oxidative desulfurization reactions

With the increasingly stringent standards for limiting sulfide content in liquid fuels, oxidative desulfurization (ODS) has become a promising ultra-deep desulfurization process in fuel desulfurization. TS-1 zeolites show great potential as catalysts for ODS reactions, due to its remarkable oxidation activity at low temperatures and pressure. However, the inherent microporous structure of conventional TS-1 zeolites restricts the mass transportation and renders the active sites in the microporous space of TS-1 zeolites inaccessible for bulky aromatic organosulfur compounds. Fabrication of hierarchical TS-1 zeolites by incorporating meso-/macropores into microporous TS-1 zeolites is an effective strategy to improve mass transportability. In recent years, abundant efforts have been dedicated to developing synthetic strategies of hierarchical TS-1 zeolite, thereby improving its catalytic performance in the ODS process. This mini-review addresses the synthetic methods of hierarchical TS-1 catalysts and their catalytic performance in the ODS reactions. In addition, some current problems and prospects of synthesis routes for constructing hierarchical TS-1 catalysts have also been revised. We expect this mini-review to shed light on the more efficient preparation strategies of hierarchical TS-1 zeolites for the ODS process. Construction of hierarchical TS-1 zeolites for the oxidative desulfurization reactions.

Atomic layer deposition of MoO3 on mesoporous γ-Al2O3 prepared by sol–gel method as efficient catalyst for oxidative desulfurization of refractory dibenzothiophene compound

MoOx/Al2O3 based catalyst has long been widely used as an active catalyst in Oxidative Desulfurization reaction due to its high stability under severe reaction conditions and high resistance to sulfur poisoning. In this context, 4 and 9 Wt.% MoO3 grafted on mesoporous γ-Al2O3 has been synthesized using the modified atomic layer deposition (ALD) method. Another MoO3/Al2O3 sample was prepared by the conventional wetness impregnation (IM) method, for comparison. The effect of the preparation methods on the metal–support interaction was evaluated using different characterization techniques; including X-ray diffraction, X-ray photoelectron spectroscopy (XPS), N2-physisorption, transmission electron microscopy (TEM), H2-temperature-programmed reduction, and FT-IR. Oxidative desulfurization (ODS) reaction of the model fuel oil was used as a probe reaction to examine the catalytic efficiency of the prepared catalysts. ALD method led to samples with much better physicochemical properties than those of the prepared one via the impregnation method. However, the 9 Wt.% MoO3/Al2O3 (ALD) catalyst in the ODS reaction of model fuel oil shows remarkable catalytic performance with ~80%, which has been attributed to the more Mo6+ surface concentrations relative to Al3+ with large pore diameter and surface area. The kinetic study shows that the ODS of DBT follows a pseudo-first-order rate reaction.