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【期刊论文】Advances in the study of hydrogen transfer to model compounds for coal liquefaction
魏贤勇, Xianyong Wei a, *, Eisuke Ogata b, Zhimin Zong a, Shilu Zhou a, Zhihong Qin a, Jianzhou Liu a, Kai Shen a, Hongqi Li a
Fuel Processing Technology 62(2000)103-107,-0001,():
-1年11月30日
The advances in the study of hydrogen transfer to model compounds for coal liquefaction are reviewed. The results from many model reactions indicate that molecular hydrogen promotes thermolysis, hydrogenation, and hydrocracking of model compounds, whereas hydrogen-donating solvents inhibit the reactions. Unlike metallic catalysts such as Fe, Pd, and Ni, their sulfides catalyze radical hydrogen transfer to model compounds. The reactivities of model compounds toward hydrocracking depend not only on their hydrogen-accepting abilities, but also on their adsorption strength on catalyst surface and the stabilities of the resulting leaving groups.
Model compound, Coal liquefaction, Hydrogen transfer
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魏贤勇, Hong Zhang, * Ming Zhou, Chao Wang, Ming Sun, Mei Li, and Xianyong Wei
,-0001,():
-1年11月30日
Accurate calibration of mineral composition on calorific value (CV) is essential to gangue utilization, cement production, etc. In this paper the influence of typical minerals on the CV of an anthracite is quantitatively studied. The results indicate that the decomposing rate of calcite decreases with the increase of calcite content during the CV test process. The deviation of CV resulting from calcite decomposition can be calculated according to its decomposing rate, which does not change with the origin of calcite. Kaolinite is transformed mainly to an amorphous solid and some to mullite. Its deviation of CV can be deduced by assuming that kaolinite is totally transformed to an amorphous solid. The complete combustion of pyrite contributes to the increase of CV. The influence of quartz and gypsum can be neglected, as the former does not change during the test and the latter has little heat effect. The composite influence of different minerals on CV can be calibrated according to that of separate minerals when total mass fraction of minerals is high. If the mass fraction is relatively low, overall heat effect produced by each mineral is a little lower than the CV actually determined.
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【期刊论文】Cu2+-Exchanged Zeolites as Catalysts for Phenol Hydroxylation with Hydrogen Peroxide
魏贤勇, Jun Wang, †, JI, Jung-Nam Park, Han-Cheol Jeong, ‡, Kwang-Sik Choi, Xian-Yong Wei, ⊥, Suk-In Hong, §, and Chul Wee Lee*
Energy & Fuels 2004, 18, 470-476,-0001,():
-1年11月30日
The Cu2+-exchanged NaY, HY, USHY, Hβ, and HZSM-5 zeolites were prepared and evaluated in phenol hydroxylation with hydrogen peroxide using an atmospheric batch reactor. CuNaY, CuHY, and CuHβ catalysts were found to be more active than TS-1 or a simple homogeneous copper nitrate catalyst under similar reaction conditions. Both zeolite type and copper content in the zeolite catalyst were revealed to exert critical impact upon the catalytic activity in phenol hydroxylation. Reaction time, reaction temperature, and the molar ratio of phenol to hydrogen peroxide also remarkably influenced the reaction results. The addition of a small amount of hydrochloric acid to the reaction systems significantly enhanced the phenol conversion, hydroxylation selectivity, and reaction rate. The used catalysts can be regenerated completely by calcination at 450℃ for 4h in air. On the basis of ESR spectroscopy, the relationship between catalytic activity and copper loading is explained and the hydroxyl radical is suggested as the reaction intermediate.
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魏贤勇, Zhen-Xue Liu and Ze-Chang Liu, Zhi-Min Zong and Xian-Yong Wei*, Jun Wang†, and Chul Wee Lee
Energy & Fuels 2003, 17, 424-426,-0001,():
-1年11月30日
Longkou brown coal was oxidized by H2O2 at 40℃ for 10h. Water-phase fraction from the reaction mixture was extracted with chloroform to afford chloroform-soluble, chloroform-insoluble but water soluble (CIWS) and solid subfractions. A series of heteroatom(s)-containing organic compounds were detected with GC/MS from the CIWS subfraction. The heteroatoms included O, N, S, and Cl
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【期刊论文】Activated Carbon-Catalyzed Hydrogenation of Polycyclic Arenes
魏贤勇, Lin-Bing Sun, Zhi-Min Zong, Jia-Hui Kou, Li-Fang Zhang, Zhong-Hai Ni, †, Gui-Yun Yu, Hong Chen, and Xian-Yong Wei*
Energy & Fuels 2004, 18, 1500-1504,-0001,():
-1年11月30日
Benzene and four polycyclic arenes (PAs) were used as substrates and their hydrogenation reactions were conducted over activated carbon (AC) at 300℃ to examine the relationship between their molecular structures and reactivities. The results show that the AC catalyzed the hydrogenation of the PAs selectively and that the reactivities of the arenes toward hydrogenation were dependent on the hydrogen-accepting abilities of the arenes and on the adsorption strengths of the arenes on the catalyst surface. The related mechanisms for hydrogen transfer were also discussed.
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