1679-06-7Relevant articles and documents
Reaction mechanisms of thioetherification for mercaptans and olefins over sulfided Mo-Ni/Al2O3 catalysts
Shen, Zhibing,Ke, Ming,Yu, Pei,Hu, Haiqiang,Song, Zhaozheng,Jiang, Qingzhe
, p. 120 - 127 (2015/02/02)
The thioetherification reaction of 1-butanethiol and 1-hexene dissolved in n-hexane was investigatedover sulfided Mo-Ni/Al2O3catalysts. The experimental results showed the catalysts have good cat-alytic performance for thioetherification reaction, but the isomerization and hydrogenation reactions of olefins over the catalysts can inhibit thioetherification reaction. As reaction temperature increases,the isomerization and hydrogenation reactions of olefins increase rapidly, however, the inhibition of thioetherification reaction also increases. The sulfur distribution and molecular structures of sulfurcompounds in the products were analyzed by the gas chromatograph with sulfur chemiluminescencedetector (GC-SCD) and the gas chromatograph/mass spectra spectrometry (GC/MS). Two possible routesof thioetherification reaction could be observed. At low temperature, the major pathway involves a directaddition of 1-butanethiol to the terminal carbon of double bond of 1-hexene. In this mechanism, the mainproduct is anti-Markovnikov adduct. At a higher temperature, the C S bond of 1-butanethiol can be sub-sequently cleaved, and the adsorbed -SH species can be formed on the catalysts. On the same time,abundant 1-hexene can be absorbed on the catalysts, as well. Therefore, the adsorbed SH species canthen recombine with adsorbed 1-hexene to form new hexyl-mercaptans, which can continue to produceanother kind of thioether (di-hexyl sulfide) with adsorbed 1-hexene. Similar with the first reaction route,the thioether of the anti-Markonikov adduct still dominates in the product.
FORMATION OF SULPHUR COMPOUNDS IN THE HYDRODENITROGENATION OF 2-METHYLQUINOLINE, 2-METHYLPIPERIDINE, INDOLE, AND ISOQUINOLINE ON A NICKEL-TUNGSTEN CATALYST IN THE PRESENCE OF HYDROGEN SULPHIDE
Cerny, Mirko,Trka, Antonin
, p. 3413 - 3420 (2007/10/02)
2-Methylquinoline, 2-methylpiperidine, indole, and isoquinoline were subjected to hydrodenitrogenation (HDN) on a sulphidized nickel-tungsten catalyst in an autoclave at 300 and 350 deg C using pure hydrogen or a hydrogen-hydrogen sulphide mixture.The neutral fraction from the HDN of 2-methylquinoline and 2-methylpiperidine contained 40 and 90percent sulphur compounds, respectively.The presence of hydrogen sulphide in the HDN of isoquinoline resulted in an enhanced fraction of the neutral moiety.A reaction mechanism is suggested for the HDN of 2-methylquinoline and 2-methylpiperidine in the presence of hydrogen sulphide, in which the latter contributes to the higher degree of conversion due to the formation of corresponding sulphur compounds.
