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Journal of Natural Gas Chemistry 2003年第3期12卷 195-200页

作者： Zhenxing Chen, Honggui Li, Lingsen WangState Key Laboratory for Powder Metallurgy, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China State Key Laboratory for Powder Metallurgy College of Chemistry and Chemical Engineering Central South University Changsha 410083 China

Radio frequency plasma was used to prepare a vanadium catalyst. The resultsshowed that activating time of the catalyst could be shortened quickly and the catalytic activitywas improved to some extent with the use of plasma. catalyst Ls-9 was prepared under an optimalcondition of 40 W discharge power, 10 min discharge time and 8 Pa gas pressure. The catalyticactivity was up to 54.7% at 410℃, which was 2.2% higher than that of the Ls-8 catalyst. Only 10 minwas needed to activate the catalyst with plasma, which was 1/9 of the traditional calcination time.For Ls-9, both the endothermic as well as the exothermic peaks detected by differential thermalanalysis shifted to higher temperatures obviously, indicating that its crystal phase could melteasily. There existed an apparent endothermic peak at 283℃. SEM photographs showed a uniform sizedistribution. It is inferred that the quadrivalent vanadium compound may exist mainly in the form ofVOSO_4.

关键词： plasma activation dispersion vanadium catalyst low-temperature activity

ETHYLENE/1-HEXENE COPOLYMERIZATION BY SALICYLALDIMINATO vanadium(Ⅲ) COMPLEXES ACTIVATED WITH DIETHYLALUMINUM CHLORIDE

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Chinese Journal of Polymer Science 2011年第5期29卷 627-633页

作者：李悦生 State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences

Mono salicylaldiminato vanadium（Ⅲ） complexes （1a-1f） [RN = CH（ArO）]VC12（THF）2 （Ar = C6H4 （1a-1e）, R = Ph, 1a; R = p-CFaPh, 1b; R = 2,6-Me2Ph, 1c; R = 2,6-iPrEPh, 1d; R = eyclohexyl, 1e; Ar = C6HEtBU2（2,4）, R = 2,6-iPrEPh, 1f） and bis（salicylaldiminato） vanadium（III） complexes （2a-2f） [RN ： CH（ArO）]EVCI（THF）x （Ar = C6H4 （2a-2e）, x = 1 （2a-2e）, R = Ph, 2a; R = p-CF3Ph, 2b; R = 2,6-Me2Ph, 2c; R = 2,6-iPr2Ph, 2d; R = cyclohexyl, 2e; Ar = C6HEtBU2（2,4）, R = 2,6-iPrEPh, x = 0, 2f） have been evaluated as the active catalysts for ethylene/1-hexene copolymerization in the presence of Et2A1C1. The ligand substitution pattern and the catalyst structure model significantly influenced the polymerization behaviors such as the catalytic activity, the molecular weight and molecular weight distribution of the copolymers etc. The highest catalytic activity of 8.82 kg PE/（mmolv.h） was observed for vanadium catalyst 2d with two 2,6-diisopropylphenyl substituted salicylaldiminato ligands. The copolymer with the highest molecular weight was obtained by using mono salieylaldiminato vanadium catalyst 1 f having ligands with tert-butyl at the ortho and para of the aryloxy moiety.

关键词： Ziegler-Natta polymerization Copolymerization vanadium catalyst Polyolefin.

ETHYLENE POLYMERIZATION AND ETHYLENE/HEXENE COPOLYMERIZAION WITH VANDIUM catalystS BEARING THIOPHENOL-PHOSPHINE LIGANDS

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Chinese Journal of Polymer Science 2013年第6期31卷 885-893页

作者： Sen-wang Zhang Yan-guo Li Ling-pan Lu 李悦生 State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences

vanadium（III） complexes bearing thiophenol-phosphine ligands （2a-2b）（2-R-6-PPh2-C6H2S） VC12（THF）2 （2a： R = H; 2b： R = MeaSi） were prepared from VCla（THF）3 by treating with 1.0 equiv of the ligand in tetrahydrofuran in the presence of excess triethylamine. The two complexes were characterized by FTIR and mass spectra as well as elemental analyses. On activation with Et2AIC1, these complexes exhibited high catalytic activities （up to 22.1 kg PE/（mmolv.***.bar）） even at high temperature （70 ℃）, and produced high molecular weight polymers with unimodal molecular weight distributions, indicating the polymerization took place in a single-site nature. This result may be attributed to benefits of introduction of second-row donor atoms for adjusting charge density of the vanadium centers. In addition, these complexes also exhibited high catalytic activities for ethylene/1-hexene copolymerization. Catalytic activity, comonomer incorporation and polymer molecular weight can be controlled in a wide range by the variation of catalyst structure and the reaction parameters such as A1/V molar ratio, comonomer feed concentration and polymerization reaction temperature.

关键词： Ziegler-Natta polymerization vanadium catalyst Polyethylene Copolymerization.

Oxidation of glyoxal to glyoxylic acid by oxygen over V_2O_5/C catalyst

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Chinese Chemical Letters 2008年第2期19卷 245-248页

作者： Yu Lan Niu Zheng Xu Min Li Rui Feng Li Key Laboratory of Coal Science and Technology MOE Institute of Special Chemicals Taiyuan University of TechnologyTaiyuan 030024 PR China Department of Chemical Engineering Taiyuan Institute of Technology Taiyuan 030008 PR China

A novel vanadium oxide catalyst supported on active carbon was prepared by an incipient wetness impregnation method, and the precursor was obtained from oxalic acid aqueous solutions of NH4VO3. The catalyst was applied liquid phase oxidation of glyoxal to glyoxylic acid. It was found that V2O5/C catalyst exhibited obvious activity for glyoxal oxidation. Glyoxylic acid could be obtained without pH regulation during the reaction. By using this catalyst, the conversion of glyoxal and the yield of glyoxalic acid were 29.2% and 13.6%, respectively at 313 K and oxygen flow 0.1 L/rain after reaction for 10 h.

关键词： Glyoxal Glyoxylic acid vanadium catalyst Oxidation

Effective VTeO/SBA-15 catalyst Prepared by Precursor Method for the Selective Oxidation of Propane to Acrolein

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Chemical Research in Chinese Universities 2008年第6期24卷 793-797页

作者： FENG Mao-ying HUANG Chuan-jing WENG Wei-zheng WAN Hui-lin XU Qin ZHOU Zhao-hui College of Chemistry and Chemical Engineering State Key Laboratory for Physical Chemistry of Solid Surface National Engineering Laboratory for Green Chemical Productions of Alcohols Ethers and Esters Xiamen University Xiamen 361005 P. R. China

Precursor decomposition was used for the preparation of VTeO/SBA-15 catalyst for the selective oxidation of propane to acrolein. The catalyst shows a better performance compared with those prepared by conventional impregnant method. A yield of 9.3% of acrolein was achieved with 2% V loadings at 500 ℃. XRD, N2-adsorption, H2-TPR, Py-IR and XPS measurements were used to unclose the relationship between the structure and performance of the catalyst.

关键词： Acrolein Propane vanadium catalyst Precursor decomposition

Activity Enhancement of vanadium catalysts with Ultrasonic Preparation Process for the Oxidation of Sulfur Dioxide

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Journal of Natural Gas Chemistry 2003年第2期12卷 139-144页

The effect of ultrasonic cavitations on the activity of vanadium catalysts atlow temperatures for the oxidation of sulfur dioxide, in which refined carbonized mother liquor hadbeen added, was investigated. Twenty minutes were needed to produce obvious cavitations when thecatalyst raw material was treated in the 50 W ultrasonic generator. However, only 10 minutes wouldbe needed in a 150 W ultrasonic generator. The higher the temperature of the wet material, the lesstime was needed to produce cavitations, and the optimal temperature was 60℃. The water content inthe wet material mainly affected the quantity of cavitations. Ls-8 catalyst was prepared usingultrasonic. Its activity for conversion of SO_2 reached to 52.5% at 410℃ and 4.2% at 350℃. Thedifferential thermal analyses indicate that both endothermic peaks and exothermic peaks noticeablyshifted forward compared with Ls catalyst prepared without ultrasonic, and SEM results show auniform pore size distribution for Ls-8 catalyst.

关键词： ultrasonic dispersion vanadium catalyst low temperature activity sulfurdioxide cavitation