Jianzhou Gui

Deep Desulfurization of Diesel Fuel by Extraction with Task-Specific Ionic Liquids

Abstract Extraction of S-compounds from diesel oil by task-specific ionic liquids has been investigated. The influences of different ionic liquids, extraction time, extraction temperature, different S-compounds, the amount, and the recycling of ionic liquid were studied. This process is capable of removing up to 56% of dibenzothiophene in model diesel oil under optimum extraction conditions. At the same time, this process was applied to the real predesulfurized diesel oils. The results indicate that such a process could be an alternative to common hydrodesulfurization for deep desulfurization.

Synthesis and Characterization of Task‐Specific Ionic Liquids Possessing Two Brönsted Acid Sites

Abstract Task‐specific ionic liquids possessing two Brönsted acid sites with –COOH, HSO− 4, or H2PO− 4 groups have been designed, synthesized, and characterized. Under mild conditions and without any additional organic solvent, the esterification of isopropanol by chloroacetic acid could be carried out in these new task‐specific ionic liquids. In comparison with most of acidic ionic liquids in current use, these ionic liquids are halogen free and more environmentally benign as media and catalysts.

Deep removal of sulfur from real diesel by catalytic oxidation with halogen-free ionic liquid

A halogen-free task-specific ionic liquid (TSIL) of 1-(2-carboxylic acid) ethyl-3-methylimidazolium bisulfate ([(CH2)2COOHmim] [HSO4]) is applied for deep oxidative desulfurization of real diesel as a catalyst and reaction media. The sulfur level of real diesel can be reduced from 200 to 20.5 μg/g at room temperature with small amount of ionic liquid using H2O2 as an oxidant. The used ionic liquid can be easily recycled and no obvious decrease in catalytic activity can be found after recycling five times.

One-Pot Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones Catalyzed by Acidic Ionic Liquids Under Solvent-Free Conditions

Abstract The acidic ionic liquids were new catalysts for the one-pot Biginelli reaction coupling of aldehyde, 1,3-dicarbonyl compound, and urea to afford the corresponding dihydropyrimidinones in good yields under solvent-free conditions. The catalysts could be recycled and reused five times without a noticeable decrease in catalytic activity.

Oxidative Aromatization of Hantzsch 1,4-Dihydropyridines Catalyzed by Ferric Perchlorate in Ionic Liquids with Air

A variety of Hantzsch 1,4-dihydropyridines were oxidized to the corresponding pyridines catalyzed by a catalytic amount of ferric perchlorate. The reaction was carried out in ionic liquid at room temperature, and the products were isolated in good to excellent yields. At the same time, the catalytic system was found to be reusable.

New Simple Synthesis Route for Decatungstate Hybrids: Novel Thermo-Regulated Phase Transfer Catalysts for Selective Oxidation of Alcohols

A generalized synthesis method for decatungstate hybrids from bisulfate-based acidic ionic liquids was reported. N-butylpyridinium decatungstate [bPy]4W10O32 and 1-butyl-3-methylimidazolium decatungstate [bmIm]4W10O32 were synthesized and have been demonstrated to be good thermo-regulated phase transfer catalysts in an organic-solvent-free selective oxidation of alcohols under mild conditions. Advantages of heterogeneous and homogeneous catalysis are combined here, provided good self-separated and ease-of-recycling catalysts.Graphical AbstractDecatungstates hybrids were synthesized in high yields directly from bisulfate-based ionic liquids, and used as novel catalysts in selective oxidation of alcohols to aldehydes or ketones. A homogeneous phase can be induced during reaction, and the catalyst could be self separated after reaction.

Deep Oxidative Desulfurization of Real Diesel Catalyzed by Na2WO4 in Ionic Liquid

An effective deep oxidative desulfurization process, catalyzed by Na2WO4 and ionic liquid, was developed for real diesel prehydrotreated. A lower amount of ionic liquid was used, while good catalytic oxidation activity could be obtained under mild conditions. The sulfur content in the real diesel can decrease from the initial 200 to 23.2 ppm after the oxidative desulfurization process, and the sulfur removal rate can reach 88.4%. The catalytic system can be recycled directly after vacuum drying, and there is no obvious change on catalytic activity after recycling five times.

Adsorption structures of heterocyclic sulfur compounds on Cu(I)Y zeolite : a first principle study

Abstract The adsorption configurations of benzothiophene (BT), dibenzothiophene (DBT) molecules and their derivatives, 4-methylbenzothiophene (4-MBT) and 4,6-dimethyl dibenzothiophene (4,6-DMDBT), on a Cu(I)Y zeolite were studied by using a density functional theory (DFT) method. The η2 adsorption mode through the C=C bond of the thiophenic ring on the zeolite has been found to be energetically preferred for the BTs, abundant in gasoline, while for the DBTs, mainly available in diesel fuel, the η1S adsorption mode is the most preferential one, implying that the competitive adsorption of aromatics over S-compounds is stronger in gasoline than that in diesel fuels. These results can be ascribed to the difference in the aromaticity and the molecular features of the heterocyclic sulfur compounds.

Selective oxidation of cyclohexane using a Co-M/Al2O3 catalyst without additives

Abstract Without any organic solvent or activator, the selective oxidation of cyclohexane with air to afford cyclohexanol and cyclohexanone was investigated over Co/Al2O3 and Co-M/Al2O3 (M = Cu, Zn, and Ni) catalysts prepared by sol-gel method. The activity of the catalysts decreases in the following order: Co-Ni/Al2O3 > Co/Al2O3 > Co-Zn/Al2O3 > Co-Cu/Al2O3. The optimum contents of cobalt and nickel are 4.0 wt% and 3.0 wt% in Co-Ni/Al2O3 catalyst, respectively. The best result was obtained over Co-Ni/Al2O3 catalyst with a conversion of 9.9% and a selectivity of 94.6% and the ratio of cyclohexanone to cyclohexanol of 2.8 when the reaction was carried out at 443 K for 120 min under 4.5 MPa, and catalytic activity did not change after five consecutive reactions.

Aromatization of n-Hexane Under Microwave Irradiation

Abstract The aromatization of n-hexane over HZSM-5 and ZnNi/HZSM-5 catalysts has been investigated using two different heating methods: microwave irradiation (MW) and conventional heating (CH). The results indicate that the aromatics and BTX yields under MW are higher than those under CH. n-Hexane aromatization mechanism under MW was similar to that under CH at the temperature below 673 K. However, the mechanism of n-hexane aromatization was different at the temperature from 673 K to 753 K. The higher the reaction temperature is, the more condensed-nucli aromatics are produced. Therefore, MW requires the lower reaction temperature when equal yields of aromatics and BTX are obtained.