Activation energy of the reaction between hexacyanoferrate (Ш) and thiosulfate ions catalyzed by platinum nanoparticles confined in nanometer space

Pt nanoparticles (NPs) have been successfully encapsulated in SBA-15 mesoporous silica support. The silica was firstly functionalized by polyaminoamine (PAMAM) dendrimers with various generations and provided different nanometer space for Pt NPs. The growth of Pt NPs is restricted by the double confinement effect of PAMAM dendrimers and SBA-15 mesopores. The Pt NPs can be precisely controlled to localize inter- or intradendrimeric within SBA-15 tunnels. The different pore structures of Gn-PAMAM-SBA-15 (Gn-PS15) support have great influence on the catalytic performance of the encapsulated Pt NPs. The blocking structure of higher generation Gn-PS15 support debased the catalytic performance and increased the activation energy of reaction between Fe(CN)(6)(3-) and S(2)O(3)(2-) in a certain degree.     

Synthesis of Olive‐Shaped Mesoporous Platinum Nanoparticles (MPNs) with a Hard‐Templating Method Using Mesoporous Silica (SBA‐15)

Well‐ordered mesoporous Pt nanoparticles (MPNs) with uniform olive shapes are synthesized by using two‐dimensional (2D) hexagonal mesoporous silica (SBA‐15) as a hard template. The average particle sizes are controllable in the range of 150 to 230 nm by changing the reduction time. Low‐angle XRD profiles for the obtained MPNs show three distinct peaks assignable to the (10), (11), and (20) planes of a highly ordered 2D hexagonal symmetry. From high‐magnification SEM images, periodically arranged Pt nanowires are observed clearly, which are a negative replica of the 2D hexagonally ordered mesoporous silica (SBA‐15). Furthermore, the single crystallinity of the Pt fcc structure coherently extends over the whole particles. As a result of such unique character as well as high surface area, the obtained MPNs show distinctly enhanced electrocatalytic properties for methanol oxidation reaction compared to other Pt samples, such as Pt black.     

Electrical double-layer capacitor performance of nitrogen-doped ordered mesoporous carbon prepared by nanotemplating method

In this work, the electrical double-layer capacitive properties of nitrogen-doped ordered mesoporous carbons (N-OMCs) were investigated. Ordered mesoporous carbons (OMCs) with 3D body-centered Ia3d structure has been prepared by KIT-6 mesoporous silica as a hard template with aniline for N-OMC and sucrose for Su-OMC as a carbon precursor. Using the different carbon precursor, moderate amounts of nitrogen atoms could be doped to the OMC structures. The obtained materials were characterized by powder X-ray diffraction (XRD), nitrogen adsorption isotherms at 77 K, elemental analysis, and X-ray photoelectron spectroscopy (XPS). Prepared OMCs had mesopore properties such as a high surface area with narrow pore-size distribution. From cyclic voltammograms (CVs) test, N-OMC compared to Su-OMC exhibit higher capacitance and fast charge/discharge characteristics, which results from their pseudo-capacitive effect of incorporated nitrogen atoms. It was thought that N-OMC prepared by the nanotemplating method with KIT-6 and aniline were suitable electrode materials for electrical double-layer capacitors.     

有序介孔三氧化二锰负载PdPt合金:一种高效的甲烷催化燃烧催化剂

甲烷作为一种清洁廉价的碳氢能源,广泛应用于运输业和其它工业领域.但是其本身是一种比二氧化碳导致全球变暖效应更强的温室气体,而且甲烷直接燃烧会产生其它污染物,比如一氧化碳、氮氧化物、未充分燃烧的碳氢化合物等.因此有必要开展有关甲烷催化燃烧的研究工作,以大幅度降低起燃温度,提高燃烧效率,有效地减少污染副产物的产生.由于具有较好的低温催化活性,Pd基催化剂常用于甲烷的催化燃烧.但是Pd基催化剂也存在一些亟需解决的问题,比如在催化燃烧过程中活性相结构不稳定.PdO通常被认为是碳氢化合物催化氧化中的活性相,但是在高温下PdO分解为Pd,导致催化活性下降.PdO遇到含水或硫的化合物时会生成惰性的Pd(OH)2或稳定的硫化物,造成活性物种的流失,从而降低催化剂的性能.如果在材料中添加另一种贵金属Pt,使之与Pd一起形成贵金属合金,则可提高其低温催化燃烧的活性,增加Pd基催化剂的热稳定性以及抗水和抗硫能力.另一方面,过渡金属氧化物价格便宜,热稳定性以及抗硫性较好,也常作为甲烷燃烧的催化剂.其中三氧化二锰由于具有可变的氧化态以及较好的储氧能力受到了广泛关注.本课题组采用KIT-6作为硬模板,先合成具有有序介孔结构的Mn2O3(meso-Mn2O3)纳米催化剂,然后通过聚乙烯醇(PVA)保护的液相共还原法分别制备meso-Mn2O3担载Pd,Pt及PdPt合金的纳米催化剂(x(PdyPt)/meso-Mn2O3;x=(0.10-1.50)wt%;Pd/Pt摩尔比(y)=4.9-5.1).XRD结果表明,合成的meso-Mn2O3具有立方相晶体结构.其BET比表面积为106 m2/g.由TEM照片可观察到粒径范围为2.1?2.8 nm的贵金属纳米颗粒均匀分散在meso-Mn2O3表面.通过XPS分析可知,结合能在529.6和531.2 eV的峰可分别归属于晶格氧(Olat)和表面吸附氧(Oads).Pd0和Pd2+以及Pt0和Pt2+也均可通过曲线拟合后进行分峰确定.XPS定量分析结果表明,样品的Oads/Olat摩尔比有如下顺序:1.41(Pd5.1Pt)/meso-Mn2O3(0.77)>1.40Pd/meso-Mn2O3(0.69)>0.72(Pd5.1Pt)/meso-Mn2O3(0.65)>1.42Pt/meso-Mn2O3(0.63)>0.07(Pd4.9Pt)/meso-Mn2O3(0.53)>0.07(Pd4.9Pt)/bulk-Mn2O3(0.52)>meso-Mn2O3(0.45),这与其催化活性的顺序一相致.该结果表明,高的吸附氧物种浓度有利于甲烷催化燃烧.负载Pd,Pt或PdPt以后的样品的表面吸附氧物种浓度显著提高,催化活性最好的1.41(Pd5.1Pt)/meso-Mn2O3样品具有最高的吸附氧物种浓度.负载PdPt合金可有效提高催化剂对甲烷燃烧的催化活性.1.41(Pd5.1Pt)/meso-Mn2O3催化剂的活性最好:在空速为20000 mL/(g.h)的条件下,甲烷燃烧的T10%,T50%和T90%分别为265,345和425oC.此外,还考察了引入一定量的SO2,CO2,H2O和NO对甲烷在1.41(Pd5.1Pt)/meso-Mn2O3催化剂上氧化反应的影响,发现引入少量的Pt可提高催化剂抗SO2,CO2和H2O的能力,但是NO对甲烷燃烧的还原效应也不可忽视.基于催化剂物化性质的表征结果和活性数据,我们认为1.41(Pd5.1Pt)/meso-Mn2O3优异的催化性能与其拥有高质量的三维有序多孔结构、高的吸附氧物种浓度、优良的低温还原性以及Pd-Pt合金与meso-Mn2O3载体之间的强相互作用有关.     

Polymeric Carbon Nitride/Mesoporous Silica Composites as Catalyst Support for Au and Pt Nanoparticles

Small and homogeneously dispersed Au and Pt nanoparticles (NPs) were prepared on polymeric carbon nitride (CN_x)/mesoporous silica (SBA‐15) composites, which were synthesized by thermal polycondensation of dicyandiamide‐impregnated preformed SBA‐15. By changing the condensation temperature, the degree of condensation and the loading of CN_x can be controlled to give adjustable particle sizes of the Pt and Au NPs subsequently formed on the composites. In contrast to the pure SBA‐15 support, coating of SBA‐15 with polymeric CN_x resulted in much smaller and better‐dispersed metal NPs. Furthermore, under catalytic conditions the CN_x coating helps to stabilize the metal NPs. However, metal NPs on CN_x/SBA‐15 can show very different catalytic behaviors in, for example, the CO oxidation reaction. Whereas the Pt NPs already show full CO conversion at 160 °C, the catalytic activity of Au NPs seems to be inhibited by the CN_x support.     

Rigid nanoscopic containers for highly dispersed, stable metal and bimetal nanoparticles with both size and site control

We demonstrate a novel strategy for the preparation of mesoporous silica-supported, highly dispersed, stable metal and bimetal nanoparticles with both size and site control. The supporting mesoporous silica, functionalized by polyaminoamine (PAMAM) dendrimers, is prepared by repeated Michael addition with methyl acrylates (MA) and amidation reaction with ethylenediamine (EDA), by using aminopropyl-functionalized mesoporous silica as the starting material. The encapsulation of metal nanoparticles within the dendrimer-propagated mesoporous silica is achieved by the chemical reduction of metal-salt-impregnated dendrimer-mesoporous silica by using aqueous hydrazine. The site control of the metal or bimetal nanoparticles is accomplished by the localization of inter- or intradendrimeric nanoparticles within the mesoporous silica tunnels. The size of the encapsulated nanoparticles is controlled by their confinement to the nanocavity of the dendrimer and the mesopore. For Cu and Pd, particles locate at the lining of mesoporous tunnels, and have diameters of less than 2.0 nm. For Pd/Pt, particles locate at the middle of mesoporous tunnels and have diameters in the range of 2.0-4.2 nm. The Pd and Pd/Pt nanoparticles are very stable in air, whereas the Cu nanoparticles are stable only in an inert atmosphere.     

Synthesis of highly ordered mesoporous crystalline WS(2) and MoS(2) via a high-temperature reductive sulfuration route

A high-temperature reductive sulfuration method is demonstrated to synthesize highly ordered mesoporous metal sulfide crystallites by using mesoporous silica as hard templates. H2S gas is utilized as a sulfuration agent to in situ convert phosphotungstic acid H3PW12O40.6H2O to hexagonal WS2 crystallites in the silica nanochannels at 600 degrees C. Upon etching silica, mesoporous, layered WS2 nanocrystal arrays are produced with a yield as high as 96 wt %. XRD, nitrogen sorption, SEM, and TEM results reveal that the WS2 products replicated from the mesoporous silica SBA-15 hard template possess highly ordered hexagonal mesostructure (space group, p6mm) and rodlike morphology, analogous to the mother template. The S-W-S trilayers of the WS2 nanocrystals are partially oriented, parallel to the mesochannels of the SBA-15 template. This orientation is related with the reduction of the high-energy layer edges in layered metal dichalcogenides and the confinement in anisotropic nanochannels. The mesostructure can be 3-D cubic bicontinuous if KIT-6 (Iad) is used as a hard template. Mesoporous WS2 replicas have large surface areas (105-120 m2/g), pore volumes ( approximately 0.20 cm3/g), and narrow pore size distributions ( approximately 4.8 nm). By one-step nanocasting with the H3PMo12O40.6H2O (PMA) precursor into the mesochannels of SBA-15 or KIT-6 hard template, highly ordered mesoporous MoS2 layered crystallites with the 2-D hexagonal (p6mm) and 3-D bicontinuous cubic (Iad) structures can also be prepared via this high-temperature reductive sulfuration route. When the loading amount of PMA precursor is low, multiwalled MoS2 nanotubes with 5-7 nm in diameter can be obtained. The high-temperature reductive sulfuration method is a general strategy and can be extended to synthesize mesoporous CdS crystals and other metal sulfides.     

Synthesis and microwave absorbing properties of highly ordered mesoporous crystalline NiFe2O4

Highly ordered mesoporous NiFe(2)O(4) with excellent microwave absorption properties has been synthesized by using mesoporous silica (KIT-6) as a hard template.     

Catalytic upgrading of lignin derived bio-oil model compound using mesoporous solid catalysts

The catalytic upgrading of a lignin-derived bio-oil model compound, the hydrodeoxygenation of guaiacol, was performed using mesoporous solid catalysts. Platinum supported on silica and mesoporous silica (SBA-15 and KIT-6) were used as catalysts. The level of platinum incorporation and aluminum grafting did not alter the physical properties of the supports, such as surface area and pore size distribution. On the other hand, these treatments drastically affected the catalytic activities. A catalyst with platinum alone converted guaiacol to oxygenate compounds. In contrast, a series of catalysts with both platinum incorporation and aluminum grafting enhanced hydrodeoxygenation by converting guaiacol into hydrocarbons (cyclohexane and benzene). A comparison of the catalyst supports revealed the ordered mesoporous silica, SBA-15 and KIT-6, with high surface area, to have a higher hydrocarbon yield than conventional silica.     

氧化钨介孔材料的制备与表征

以介孔二氧化硅(KIT-6)为硬模板, 硅钨酸为钨源, 用硬模板法制备WO3-SiO2复合材料, 再利用HF除去二氧化硅, 得到了介孔三氧化钨材料. 用X射线衍射(XRD)、能量扩散X射线(EDX)、高分辨透射电镜(HRTEM)、N2吸附-脱附等表征手段, 对制备复合材料的物料比、煅烧温度以及不同分散剂等条件进行了考察. 结果表明, 硅钨酸与硅介孔的物料比(m(WO3)/m(SiO2))在3:1到4:1之间, 在600-750 ℃下煅烧, 能制备结构较好的介孔氧化钨. 乙醇和蒸馏水为分散剂时, 用乙醇为分散剂所得的介孔WO3材料具有更高的比表面积和孔体积.     

Immobilization of chiral oxazaborolidine catalyst over highly ordered 3D mesoporous silica with Ia3d symmetry for enantioselective reduction of prochiral ketone

Here we demonstrate for the first time the encapsulation of a chiral oxazaborolidine complex in the 3D mesoporous channels of an amine functionalized KIT-6 material via covalent bonding through a post-synthetic approach. The physico-chemical properties of the pure and immobilized KIT-6 catalysts were obtained by various techniques such as XRD, nitrogen adsorption, HRSEM, UV-Vis diffuse reflectance spectroscopy, and FT-IR spectroscopy. It has been found that the structural stability of the KIT-6 was not affected even after the immobilization of a significant amount of chiral ligand inside the mesoporous channels of the support. However, the values of structural parameters such as the specific surface area and the specific pore volume of the KIT-6 support was significantly lower than the pure KIT-6 support. The chemical interaction between the chiral ligand inside the mesochannels and the KIT-6 support was also confirmed by UV-Vis and FT-IR spectroscopy. The chiral catalytic performance of the immobilized catalysts for the enantioselective reduction of aromatic prochiral ketones was demonstrated and the results were compared with chiral catalyst immobilized supports with uni-dimensional porous structures, such as MCM-41 and SBA-15. Among the catalysts studied, chiral catalyst immobilized KIT-6 showed the highest performance with a high product yield and a high enantioselectivity due to its 3D porous structure with two continuous and interpenetrating systems of chiral channels and an interwoven 3D cylindrical type pores of Ia3d symmetry. The catalyst also exhibited much better recycling capability than other chiral catalyst supported mesoporous materials used in the study.     

Synthesis and magnetic investigation of ordered mesoporous two-line ferrihydrite

We report here for the first time on the synthesis and characterization of ordered mesoporous two-line ferrihydrite. Ordered mesoporous ferrihydrite has been prepared via the nanocasting route. Two types of ordered mesoporous silica, two-dimensional hexagonal SBA-15 and three-dimensional cubic KIT-6, were employed as hard templates. The magnetic behavior of ferrihydrite replicas with an average diameter of about 7 nm was investigated by direct current magnetometry. The temperature dependence of magnetization shows a superparamagnetic transition around 70 K. Field-induced changes in the low-field behavior of the magnetization were observed below 30 K. The results are explained assuming a spin-glass-like state of the surface spins. The 2D hexagonal two-line ferrihydrite showed very large coercivity up to 1.6 kOe at 5 K.     

Robust hydrogen production from HCOOH over amino-modified KIT-6-confined PdIr alloy nanoparticles

Formic acid（FA）, which can be produced via CO2reduction and biomass conversion, has received extensive interest as a convenient and safe hydrogen carrier due to its wide range of sources, renewable,high hydrogen content（4.4 wt%）, and convenient storage/transportation. Designing highly efficient catalysts is the main challenge to realize the hydrogen production from FA. In this work, well-dispersed and electron-rich Pd Ir alloy nanoparticles with a size of 1.8 nm are confined in amino-modified 3D...     

Mesoporous silica hybrid membranes for precise size-exclusive separation of silver nanoparticles

One-dimensional (1D) nanomaterials have unique applications due to their inherent physical properties. In this study, hexagonally ordered mesoporous silica hybrid anodic alumina membranes (AAM) were synthesized using template-guided synthesis with a number of nonionic n-alkyl-oligo(ethylene oxide), Brij-type (C(x)EO(y)), which are surfactants that have different molecular sizes and characteristics. The hexagonal mesoporous silicas are vertically aligned in the AAM channels with a predominantly columnar orientation. The hollow mesostructured silicas had tunable pore diameters varying from 3.7 to 5.1 nm. In this synthesis protocol, the surfactant molecular natures (corona/core features) are important for the controlled generation of ordered structures throughout AAM channels. The development of ultrafiltration membranes composed of silica mesostructures could be used effectively in separating silver nanoparticles (Ag NPs) in both aqueous and organic solution phases. This would be relevant to the production of well-defined Ag NPs with unique properties. To create a size-exclusive separation system of Ag NPs, we grafted hydrophobic trimethylsilyl (TMS) groups onto the inner pores of the mesoporous silica hybrid AAM. The immobilization of the TMS groups allowed the columnar mesoporous silica inside AAM to retain this inner pore order without distortion during the separation of solution-phase Ag NPs in organic solvents that may cause tortuous-pore membranes. Mesoporous TMS-silicas inside 1D AAM channels were applicable as a size-exclusive separation system to isolate organic solution-phase Ag NPs of uniform morphology and size.     

一步制备高比表面积介孔Co3O4-CeO2及其表征

以有序介孔二氧化硅KIT-6为硬模板,硝酸钴、硝酸铈为金属源,分别在真空辅助条件和普通搅拌条件下制备了介孔CoCeOx复合氧化物。采用XRD、SEM、TEM、N2吸脱附等技术表征了复合氧化物的物化性质,并评价其氧化甲苯的性能。结果表明,在真空辅助和搅拌条件下制备的CoCeOx氧化物是由Co3O4和CeO2组成的介孔Co3O4-CeO2复合氧化物,其比表面积分别为141和89 m^2·g^-1,平均孔径分别为8.7和9.6 nm。真空辅助纳米复制过程有利于金属盐的前驱体充分填充到模板的孔隙中,去除模板后,可以得到有序的介孔复合金属氧化物。所制备介孔钴铈复合氧化物具有孔道有序性好、比表面积大的特点,在挥发性有机化合物的氧化去除方面具有一定的应用前景。     

Phosphonate-functionalized large pore 3-D cubic mesoporous (KIT-6) hybrid as highly efficient actinide extracting agent

A new type of radionuclide extraction material is reported based on phosphonate functionalities covalently anchored on the mesopore surface of 3-D cubic mesoporous silica (KIT-6). The easily prepared nanoporous hybrid shows largely superior performance in selective sorption of uranium and thorium as compared to the U/TEVA commercial resin and 2-D hexagonal SBA-15 equivalent.     

Designed Synthesis of Well‐Defined Pd@Pt Core–Shell Nanoparticles with Controlled Shell Thickness as Efficient Oxygen Reduction Electrocatalysts

Improving the electrocatalytic activity and durability of Pt‐based catalysts with low Pt content toward the oxygen reduction reaction (ORR) is one of the main challenges in advancing the performance of polymer electrolyte membrane fuel cells (PEMFCs). Herein, a designed synthesis of well‐defined Pd@Pt core–shell nanoparticles (NPs) with a controlled Pt shell thickness of 0.4–1.2 nm by a facile wet chemical method and their electrocatalytic performances for ORR as a function of shell thickness are reported. Pd@Pt NPs with predetermined structural parameters were prepared by in situ heteroepitaxial growth of Pt on as‐synthesized 6 nm Pd NPs without any sacrificial layers and intermediate workup processes, and thus the synthetic procedure for the production of Pd@Pt NPs with well‐defined sizes and shell thicknesses is greatly simplified. The Pt shell thickness could be precisely controlled by adjusting the molar ratio of Pt to Pd. The ORR performance of the Pd@Pt NPs strongly depended on the thickness of their Pt shells. The Pd@Pt NPs with 0.94 nm Pt shells exhibited enhanced specific activity and higher durability compared to other Pd@Pt NPs and commercial Pt/C catalysts. Testing Pd@Pt NPs with 0.94 nm Pt shells in a membrane electrode assembly revealed a single‐cell performance comparable with that of the Pt/C catalyst despite their lower Pt content, that is the present NP catalysts can facilitate low‐cost and high‐efficient applications of PEMFCs.     

Pd@Pt Core–Shell Nanoparticles with Branched Dandelion‐like Morphology as Highly Efficient Catalysts for Olefin Reduction

A facile synthesis based on the addition of ascorbic acid to a mixture of Na₂PdCl₄, K₂PtCl₆, and Pluronic P123 results in highly branched core–shell nanoparticles (NPs) with a micro–mesoporous dandelion‐like morphology comprising Pd core and Pt shell. The slow reduction kinetics associated with the use of ascorbic acid as a weak reductant and suitable Pd/Pt atomic ratio (1:1) play a principal role in the formation mechanism of such branched Pd@Pt core–shell NPs, which differs from the traditional seed‐mediated growth. The catalyst efficiently achieves the reduction of a variety of olefins in good to excellent yields. Importantly, higher catalytic efficiency of dandelion‐like Pd@Pt core–shell NPs was observed for the olefin reduction than commercially available Pt black, Pd NPs, and physically admixed Pt black and Pd NPs. This superior catalytic behavior is not only due to larger surface area and synergistic effects but also to the unique micro–mesoporous structure with significant contribution of mesopores with sizes of several tens of nanometers.     

Ag nanoparticles immobilized on guanidine modified-KIT-5 mesoporous nanostructure: Evaluation of its catalytic activity for synthesis of propargylamines and investigation of its antioxidant and anti-lung cancer effects

The current study involves the novel synthesis of Ag nanoparticles (Ag NPs) decorated biguanidine modified mesoporous silica KIT-5 following post-functionalization approach (KIT-5-bigua-Ag). The tiny Ag NPs were being stabilized over the in situ prepared biguanidine ligand. The high surface area material was characterized using advanced analytical methods like Fourier Transformed infrared (FT-IR) spectroscopy, N₂-adsorption–desorption isotherm, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDS), and X-ray Diffraction study (XRD). The material was having large pore cage like structure with pore diameter of 8–10 nm. TEM study displayed the particles size of deposited Ag NPs were 10–15 nm. The KIT-5-bigua-Ag nanocomposite had a significantly high surface area of 318 m²/g (BET analysis). Towards the chemical applications of the material, we headed the three-component reaction of aldehydes, amines and alkynes (A³ coupling) with good to excellent yields (70–98%) of diverse Propargylamines. The catalyst was easily isolable and reused in 8 cycles without any leaching and considerable change in its reactivity. In addition, the KIT-5-bigua-Ag nanocomposite was engaged in biological assays like study of anti-oxidant properties by DPPH mediated free radical scavenging test using BHT as a reference molecule. Thereafter, on having a significant IC50 value in radical scavenging assay, we extended the bio-application of the desired nanocomposite in anticancer study of A549 cell of human lung in-vitro conditions. In the cytotoxicity and anti-human lung studies, the nanocomposite was treated to lung cancer A549 cell line following MTT assay. The cell viability of malignant lung cell line reduced dose-dependently in the presence of KIT-5-biguanidine-Ag nanocomposite. IC50 values of the nanocomposite were observed to be 915.22 μg/mL against A549 cell line. So, these results suggest that KIT-5-bigua-Ag as a novel chemotherapeutic nanocomposite have a suitable anticancer activity against lung cell lines.     

Highly efficient mesoporous WO<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>/KIT-6 catalysts for oxidative desulfurization of dibenzothiophene with hydrogen peroxide

Oxidative desulfurization (ODS) of organic compounds containing sulfur element from a model oil was performed using tungsten oxide catalysts supported on mesoporous silica with cubic Ia3d mesostructure, well-defined mesopores (7.2 nm), high surface area (719 m²/g), and three-dimensional pore network (WO _x /KIT-6). The prepared WO _x /KIT-6 catalysts (5–20 wt% WO _x ) were characterized by X-ray diffraction analysis, N₂ sorption measurements, electron microscopy, H₂-temperature programmed reduction, Raman spectroscopy, and thermogravimetric analysis. Among the mesoporous catalysts, 10 wt% WO _x /KIT-6 exhibited the best catalytic performance. Sulfur-containing organic compounds, such as dibenzothiophene, 4,6-dimethyldibenzothiophene, and benzothiophene, were completely (100 %) removed from the model oil over 10 wt% WO _x /KIT-6 catalyst in 2 h. In addition, the catalyst could be reused several times with only slight decrease in catalytic activity.