Preparation of WO3/C Composite and Its Application in Oxidative Desulfurization of Fuel

The WO_3/C composite was successfully prepared by calcination of a mixture of WO_3 and g-C_3N_4 at 520 ℃. The as-synthesized samples were analyzed by X-ray diffraction(XRD), electronic differential system(EDS), scanning electron microscopy(SEM), infrared spectrometry(IR) and the Brunner-Emmet-Teller(BET) techniques. The WO_3/C composite, in comparison with the WO_3 and C_3N_4, features smaller particle size, bigger surface area and higher desulphurization performance. The influence of the reaction temperature, the catalyst dosage, the reaction time, the oxidant dosage, the sulfide type and the extractant dose on desulfurization reaction was studied. The results showed that the WO_3/C composite revealed a higher desulfurization activity than the WO_3. The desulfurization rate could reach up to 95.8% under optimal conditions covering a catalyst dosage of 0.02 g, a H_2O_2 amount of 0.2 mL, a 1-ethyl-3-methylimidazolium ethyl sulfate(EMIES) amount of 1.0 mL, a reaction temperature of 70 ℃ and a reaction time of 180 min. After five recycles, the desulfurization activity of catalyst did not significantly decline.

Promotion of activation ability of N vacancies to N2 molecules on sulfur-doped graphitic carbon nitride with outstanding photocatalytic nitrogen fixation ability

Nitrogen vacancies and sulfur co-doped g-C3N4 with outstanding N2 photofixation ability was synthesized via dielectric barrier discharge plasma treatment. X-ray diffraction, ultraviolet–visible spectroscopy, N2 adsorption, scanning electron microscopy, X-ray photoelectron spectroscopy, photoluminescence spectroscopy, and temperature-programmed desorption were used to characterize the as-prepared catalyst. The results showed that plasma treatment cannot change the morphology of the as-prepared catalyst but introduces nitrogen vacancies and sulfur into g-C3N4 lattice simultaneously. The as-prepared co-doped g-C3N4 displays an ammonium ion production rate as high as 6.2 mg·L^-1·h^-1·gcat^-1, which is 2.3 and 25.8 times higher than that of individual N-vacancy-doped g-C3N4 and neat g-C3N4, respectively, as well as showing good catalytic stability. Experimental and density functional theory calculation results indicate that, compared with individual N vacancy doping, the introduction of sulfur can promote the activation ability of N vacancies to N2 molecules, leading to promoted N2 photofixation performance.

Synthesis of H_(2)WO_(4)/GO and Its Oxidative Desulfurization Activity

H_(2)WO_(4)/GO catalyst was synthesized by the immersion method and was characterized by using X-ray diffraction(XRD),Fourier-transform infrared spectroscopy(FT-IR),scanning electron microscopy(SEM),and nitrogen adsorptiondesorption measurements(BET).The characterization results show that H_(2)WO_(4) has been dispersed on GO(grapheme oxide).H_(2)WO_(4)/GO was used as catalyst in the oxidative desulfurization of dibenzothiophene(DBT),with H2O2 acting as oxidant and acetonitrile acting as extraction agent.The experimental results show that the sulfur removal rate for DBT reach 99.2%,that for 4,6-dimethyldibenzothiophene(4,6-DMDBT)reach 95%and that for benzothiophene(BT)reach 42.8%under the optimal reaction conditions.Meanwhile,the recycled catalysts still exhibits good desulfurization performance after four operating cycles.The high activity and stability of catalysis is attributed to a small dose of H_(2)WO_(4),which is highly dispersed inside the layers of GO.This desulfurization reaction follows the pseudo-first-order kinetics,and the apparent activation energy of the desulfurization reaction is 18.515 kJ/mol,which indicates that the H_(2)WO_(4)/GO used as desulfurization catalyst has demonstrated good desulfurization property for DBT.

Effect of the Morphology of ZnO Support on the Desulfurization and Regeneration Performance of Ni/ZnO Catalyst

The Ni/ZnO desulfurization catalyst has been highly valued for its high desulfurization rate and low octane value loss. However, during the process of desulfurization, ZnO is prone to deactivation and the active component Ni is susceptible to agglomeration, which can affect the performance of the catalyst. In order to solve these problems, the modification of ZnO support has been extensively studied. The granular, short rod-shaped and nanowire-structured ZnO were synthesized by controlling the concentration of NaOH, and the desulfurization catalyst was prepared with ZnO serving as the support after loading of metallic Ni. The catalyst was characterized by X-ray diffraction, N2 adsorption-desorption, SEM, TEM and other analytical methods. The desulfurization performance of the catalyst was investigated with n-heptane - thiophene used as model compounds. Test results showed that the morphology and size of ZnO support has great influence on the desulfurization performance of the catalyst. Desulfurization catalyst prepared with nanowire-structured ZnO support has the best desulfurization performance, with its desulfurization rate reaching 98.2%. The result was achieved mainly due to the nanowire structure of ZnO support which could effectively restrain the agglomeration of metallic Ni on the surface and reduce the particle size of the active component of metallic Ni so as to improve its dispersion on the surface of the support. In addition, the nanowire structure can reduce the diffusion resistance of thiophene in the reaction process and provide a channel conducive to sulfur transfer and diffusion, which makes it perform well in the desulphurization reaction process and regeneration process.

A New Coordination Polymer Built of 4-(5H-tetrazol)-benzoic Acid and 3,5-Dimethyl-1H,1,2,4-Triazole Showing a Rarely Observed(3,5)-Connected lhh Topology: Synthesis, Structure, CO_2 Adsorption and Luminescent Property

A three-dimensional coordination polymer,namely {[Zn2（tzba）（dmtrz）（OH）]·3H2O}n（1,H2tzba = 4-（5H-tetrazol）benzoic acid,Hdmtrz = 3,5-dimethyl-lH,l,2,4-triazole）,was hydrothermally synthesized and characterized by single-crystal X-ray diffraction.It crystallizes in monoclinic system,P21/c space group with a = 8.018（11）,b = 21.04（3）,c = 11.069（14） A,β=91.26（3）°,V= 1867（4） A^3,Z = 4,Dc = 1.729 g/cm^3,F（000） = 984,μ= 2.614 mm^（-1）,R（F^2 〉 2σ（F^2）） =0.0612 and wR（F^2） = 0.1533.Topological analysis reveals that compound 1 is a（3,5）-connected structure with a Schlafli symbol of（4~2.6）（4~2.6~5.8~3）,which is a rarely observed lhh topology.In addition,the CO2 adsorption performance and luminescent property of 1 have also been studied.

Bitumen Recovery from Indonesian Oil Sands Using ASP(Alkali, Surfactant and Polymer) Agent

A self-developed ASP agent was used to separate bitumen from Indonesia's oil sands by its comprehensive effect and the separation condition was well investigated. The bitumen extraction conditions for industrial application were recommended to cover a mixing temperature of 80℃, a mixing time of 40 min, a mass ratio of ASP agent to oil sands of 4:10, and a floating time of 10 min. Under the above conditions, the bitumen recovery was about 86% and the residual bitumen content in tailings was about 6%. The relationship between the residual bitumen content and the particle size of tailings was studied in order to find the way to reducing the residual bitumen content in tailings. The results showed that the residual bitumen content in tailings decreased with a decreasing tailings particle size. After being milled for 30 min with a mortar, the tailings was reprocessed via extraction by means of the ASP agent, and the residual bitumen content in tailings decreased from 5.47% to 1.25%, which could comply with the disposal requirements.

Synthesis of Macro-Mesostructured γ-Al_2O_3 with Large Pore Volume and High Surface Area by a Facile Secondary Reforming Method

Through improving the aging process during synthesis of the support, γ-Al2O3 with large pore volume and high surface area was synthesized by a facile secondary reforming method. The synthesis parameters, such as the reaction temperature, the first aging temperature and the second aging temperature, were investigated. The textural properties of γ-Al2O3 were characterized by means of N2 adsorption-desorption isotherms, X-ray powder diffractometry （XRD）, scanning electron microscopy （SEM）, Fourier transform infrared （FTIR） spectroscopy and thermogravimetry （TG）. The experimental results indicated that AACH and amorphous A1OOH were the precursors of alumina, which were formed via precipitation from solutions after reaction of aluminum sulphate with ammonium hydrogen carbonate. The precursor nanocrystallites grew and re-assembled during the secondary reforming process, which resulted in an increased pore size and pore volume and a decreased bulk density. The as-synthesized γ-Al2O3 materials featured meso/macroporosity, large pore volume （2.175 cm^3/g）, high surface area （237.8 m^2/g）, and low bulk density （0.284 g/mL）.

Acid-catalyzed chemoselective C-and O-prenylation of cyclic 1,3-diketones

The chemoselective C-and O-prenylation of cyclic 1,3-diketones was achieved by tuning the prenyl source and catalyst.In the presence of the solid acid Nafion,the coupling of 1,3-cyclohexanediones with isoprene gave C-prenylated 5-chromenones.Alternatively,using prenol as the substrate with the Lewis acid Al Cl3 as the catalyst resulted in the exclusive O-prenylation of 1,3-cyclohexanediones.Notably,the resulting products could easily undergo aromatization to deliver prenylated resorcinols that are otherwise difficult to prepare.Our methodology is highly selective,atom-economical,operationally simple,easily scalable,and has potential applications throughout organic synthesis.

Preparation of Bi2WO6 and Its Ultra-Deep Oxidative Desulfurization Performance in Ionic Liquids

The micro-spheric Bi_2WO_6 was synthesized by a simple one-step hydrothermal method. Bi_2WO_6 crystals were characterized using XRD, SEM, EDS and BET techniques. Bi_2WO_6, H_2O_2 and [HMIM][BF_4] served as catalyst, oxidant and extracting agent in the oxidative desulfurization system(ODS), respectively. The influence of extraction agent type, oxidant usage, catalyst dosage, temperature, sulfur compound type and other factors on the oxidative desulfurization was studied in the present work. The experimental results demonstrate that Bi_2WO_6 possesses high activity for desulfurization of dibenzothiophene(DBT) and benzothiophene(BT). The desulfurization rate of DBT and BT in model oil could reach 98.1% in 80 minutes and 96.2% in 120min at 70℃, respectively. Moreover, the desulfurization performance of catalyst for DBT hardly changed after being recycled for 10 times.

Study on the Influence of Ni Modifying on Phase Transformation and Photocatalytic Activity of TiO_2

The Ni-modified TiO2 was synthesized using two methods including co-precipitation(Ni doped TiO2, Ni-TiO2) and wet impregnation(Ni loaded TiO2, Ni/TiO2). The surface and bulk crystalline phases of Ni-modified TiO2 were investigated by using X-ray diffractometry(XRD), UV Raman spectroscopy, TEM, and SEM. It is observed that Ni doping can promote the phase transition and grain size growth of TiO2. Moreover, the propagation of the rutile phase from the bulk into the surface region of TiO2 is increased when the Ni doping amount reaches up to 3%. However, in Ni/TiO2, it is found out that the surface and bulk phase transformation of TiO2 can be inhibited after impregnation of 1% of Ni on the TiO2. Compared with the co-precipitation method, Ni species may be more enriched in the surface of the Ni/TiO2 sample upon adoption of the impregnation method, and the direct contact of anatase particles of TiO2 is avoided. As a consequence, the phase transition in the surface and bulk region of TiO2 can be effectively inhibited by Ni loading. Additionally, the activity of the photocatalytic degradation of RhB on the 3Ni-TiO2-600 ℃ sample is higher than that on the 3 Ni/TiO2-600 ℃ sample. The phase junction formed between anatase and rutile in the surface region of 3Ni-TiO2-600 ℃ may the main reason for its high photocatalytic activity.

A New Europium Coordination Compound Supported by 4,6-Dibenzoylisophthalic Acid Ligands

A unique metal-organic framework（MOF） [Eu_2（L）_3（phen）_2]_n（1, H_2L = 4,6-dibenzoylisophthalic acid, phen = 1,10-phenanthroline） has been synthesized under hydrothermal conditions and characterized by single-crystal X-ray analysis, elemental analyses, powder X-ray diffraction, TGA measurement as well as IR spectra. The crystal is of triclinic system, space group P1, C_（90）H_（52）Eu_2N_4O_（18）, M_r = 1781.32, a = 9.8697（4）, b = 16.7466（6）, c = 22.2556（10） A, α = 87.113（3）, β = 77.575（5）, γ = 89.458（3）°, V = 3587.8（3） A^3, Z = 2, D_c = 1.649 g/cm^3, F（000） = 1780, μ（MoKα） = 1.813 mm^（-1）, Rint = 0.0181, R = 0.0260 and wR = 0.0592 for 14000 observed reflections with I 〉 2σ（I）. X-ray analysis shows that the title compound exhibits a 2D layer structure linked by L ligands with two coordination modes and two distinguished conformations, and further linked into a 3D supramolecular architecture through C-H···O weak interactions between hydrogen of phen phenyl ring and the carboxylate oxygen atom of adjacent sheets. In addition, the luminescence property of 1 was investigated.

Study on structural characteristics and adsorption performance of ultrasonic treated Mn-containing sulfur transfer agent

To prepare manganese-containing spinel sulfur transfer agent with acid peptization, ultrasonic wave is used for the first time to modify the structure of sulfur transfer agent in this work. Mini fixed bed reactor was used to investigate the effect of ultrasonic power, time and temperature on the structure and oxidation adsorption performance of sulfur transfer agent and the adsorption kinetics and mechanism of SO2 were analyzed. SEM, TEM, XRD and N2 adsorption-desorption techniques were employed to characterize and analyse the function of sulfur transfer agent. The results indicated that manganese-containing spinel is a kind of promising sulfur transfer agent and exhibits higher sulfur capacity and desulfurization degree under the selected conditions of the ultrasonic wave power of 60%, and with the treatment period for 3 h at a temperature of 60 ℃.

Synthesis,and Experimental and Theoretical Characterization of 3-(4-(Dimethylamino) benzylidene)-1,5-dioxaspiro[5.5] Undecane-2,4-dione

The title molecule, 3-（4-（dimethylamino）benzylidene）-l,5-dioxaspiro[5.5] unde- cane-2,4-dione （I）, was synthesized and characterized by elemental analysis, IR, UV-vis spectra and X-ray diffraction analysis. The compound belongs to the triclinic system, space group Pi with a = 6.3640（6）, b = 7.7404（8）, c = 16.2890（18） A, α = 86.860（2）, β = 85.837（2）, γ = 79.6720（10）°, V = 786.60（14） A3, D, = 1.331 g/cm3, and F（000） = 336. Geometrical structure of the title compound was optimized by density functional theory （DFT） using B3LYP method with 6-31G＊＊ as the basis set. The vibrational frequencies were calculated by the DFT method and the results are consistent with the observed frequencies. The electronic absorption spectra were studied with the time- dependent density functional theory （TD-DFT）, showing the calculation results in good agreement with the corresponding experimental data.

Revealing the role of electrode potential micro-environments in single Mn atoms for carbon dioxide and oxygen electrolysis

Elucidation the relationship between electrode potentials and heterogeneous electrocatalytic reactions has attracted widespread attention.Herein we construct the well-defined Mn single-atom(MnSA)catalyst with four N-coordination through a simple thermal pyrolysis preparation method to investigate the electrode potential micro-environments effect on carbon dioxide reduction reactions(CO_(2)RR)and oxygen reduction reactions(ORR).MnSA catalysts generate higher CO production Faradaic efficiency of exceeding 90%at-0.9 V for CO_(2)RR and higher H_(2)O_(2)yield from 0.1 to 0.6 V with excellent ORR activity.Density functional theory(DFT)calculations based on constant potential models were performed to study the mechanism of MnSA on CO_(2)RR.The thermodynamic energy barrier of CO_(2)RR is lowest at-0.9 V vs.reversible hydrogen electrode(RHE).Similar DFT calculations on the H_(2)O_(2)yield of ORR showed that the H_(2)O_(2)yield at 0.2 V was higher.This study provides a reasonable explanation for the role of electrode potential micro-environments.

Advancement in separation materials for blood purification therapy

Blood purification refers to the extra corporeal therapies of removing potentially toxic substances, in which blood is circulated through an adsorption system loading separation materials. High-efficient inexpensive separation materials are critical to success. In this review, separation materials such as polymers and nanomaterials are summarized and compared. Combining the advantages of the adsorptive membranes and nanomaterials, organic–inorganic hybrid/blend membranes have been developed explosively. These hybrid/blend membranes have both the characteristics of high permeability, easy fabrication, good biocompatibility of adsorptive membranes, and characteristics of fast adsorption rate and high adsorption capacity of nanomaterials. The preparation and modification methodology of the separation materials is reviewed. For affinity separation materials, the relationship of ligand chemistry, ligand density and pores of the matrix is discussed. This paper also summarizes some interesting applications in separation materials for removal of bilirubin, endotoxin, toxic metal ions, cytokine, etc.

Removal of Nitrogen Compounds from Shale Diesel Fraction Using Ionic Liquid [C_4mim]HSO_4

Ionic liquid(IL) 1-butyl-3-methylimidazolium hydrosulphate([C_4mim]HSO_4) was synthesized and its denitrogenation performance was investigated for diesel fraction with high content of nitride from oil shale. The effects of the temperature, the mass ratio of oil to IL, the mass ratio of water to IL, the extraction time, the settling time and the regeneration of IL on the N-removal efficiency were studied. Experimental results showed that the ionic liquid [C_4mim]HSO_4 exhibited excellent denitrogenation performance, and about a 90% basic N-extraction efficiency and a 71% total N-extraction efficiency were achieved under the conditions covering a temperature of 30 ℃, an oil/IL mass ratio of 7:1, a H_2O/ IL mass ratio of 2:1, an extraction time of 20 min and a settling time of 120 min. In addition, the basic N-removal efficiency can still reach 74% during five recycles of the ionic liquid.

Experimental Study on Preparation of Natural Gas Hydrate by Crystallization

In this paper, the saturated solution crystallization method is proposed to promote the formation of hydrate by means of the known similarities between the hydrate formation process and the crystallization process. In this method,adding the second phase crystals was used to replace the spontaneous formation of hydrate crystal nuclei to form hydrate.The effects of saturated Na_2SO_4, MgSO_4, NH_4HCO_3 and CuSO_4 solutions on the formation rates of natural gas hydrate and gas storage capacity were investigated. The results showed that the saturated solution had an influence on the hydrate formation process. Under the given experimental conditions, the saturated Na_2SO_4 solution showed a highest increase in the hydrate formation rate, and the average hydrate formation rate in its presence was 11.8 times higher than that obtained in the deionized water. Moreover, the largest formation rate of gas hydrates observed in the saturated Na_2SO_4 solution was 386 times bigger than that in the deionized water, and the gas storage capacity increased by 10 times. In addition, the average hydrate formation rate in the saturated Mg SO_4 solution was faster than that in water by 20 times. The largest formation rate of gas hydrates in the saturated MgSO_4 solution was 165 times faster than that obtained in the deionized water, and the gas storage capacity increased by 6.2 times. The saturated NH_4HCO_3 and saturated CuSO_4 solutions also influenced the formation process of hydrate. Therefore, the crystallization method of saturated solution can be used to achieve a highefficiency preparation of natural gas hydrates, which provides theoretical guidance for the storage of natural gas in the form of hydrate.

Removal of Nitride from Shale Diesel Fraction with FeCl3-Based Ionic Liquids

FeCl3-based ionic liquid [Bmim]Br/FeCl3 with lower viscosity was synthesized and its structure was character-ized with FT-IR spectroscopy. The denitrogenation performance of the ionic liquid was investigated using the Fushun shale diesel fraction with high nitrogen content. Experimental results showed that the ionic liquid presented good denitrogenation performance and the basic N and total N removal efficiency can reach 95.29% and 89.77% under conditions covering a tem-perature of 30 ℃, an IL/oil mass ratio of 1:1, an extraction time of 30 min, and a settling time of 2 h. Correspondingly, the basic N and total N contents in shale diesel fraction dropped from the original 5454 μg/g and 9832 μg/g to 257 μg/g and 1006 μg/g, respectively. In addition, the basic-N removal efficiency can still reach 60% at an IL/oil mass ratio of 1:7 during four recycles of the ionic liquid.

Removal of Basic Nitrogen Compounds from Coker Diesel by Eutectic Ionic Liquid

The eutectic ionic liquid （EIL） tetraethyl ammonium bromide-malonic acid （TEAB-Mal） was synthesized, with its structure characterized by the FT-IR spectroscopy and the 1H NMR spectrometry. The performance for removal of basic nitrogen compounds by EIL was studied using coker diesel as the feedstock. Experimental results showed that the EIL （TEAB-Mal） exhibited a good denitrogenation performance, leading to a 93.6% of basic N-removal efficiency under reaction conditions covering： a temperature of 30 ℃, an EIL to oil mass ratio of 1：1, an extraction time of 30 min, and a settling time of 120 min, while the basic nitrogen content in diesel dropped from 580 μg/g to 37 gg/g. In addition, the efficiency for extraction of basic N-compounds could still reach 62.9% at am EIL/oil mass ratio of 1：7 after four recycles of the EIL.

Polycrystalline Phase WO_3/g-C_3N_4 as a High Efficient Catalyst for Removal of DBT in Model Oil

The polycrystalline phase WO_3/g-C_3N_4 was synthesized under stirring using tungstenic acid(H_2WO_4) and graphitic carbon nitride(g-C_3N_4) as raw materials. The catalyst was characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),the Fourier transform infrared spectroscopy(FT-IR),and the Brunauer-Emmett-Teller analysis(BET). The polycrystalline phase WO_3/g-C_3N_4 was determined by XRD technique. The oxidative desulfurization process was investigated using WO_3/g-C_3N_4 as the catalyst, 30% hydrogen peroxide(H202) as the oxidant, and 1-butyl-3-methylimidazolium tetrafluoroborate([bmim]BF4) ionic liquids(ILs) as the extractant. The operating conditions, including H_2WO_4 amount, IL dose, H_2 O_2 volume, temperature, catalyst dosage, and types of sulfur compounds,were systematically researched. The desulfurization rate could reach 98.46% for removing dibenzothiophene(DBT) from the model oil under optimal reaction conditions. In addition, the catalytic activity was slightly decreased after five recycles of catalysts. The reaction kinetics analysis shows that the oxidative desulfurization system was in accord with the first-order reaction kinetics equation. The mechanism of oxidative desulfurization was proposed.