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  • Development of a General Non-Noble Metal Catalyst for the Benign Amination of Alcohols with Amines and Ammonia
  • 更新时间：2014-04-10；信息类型：SCI论文
  • The N-alkylation of amines or ammonia with alcohols is a valuable route for the synthesis of N-alkyl amines. However, as a potentially clean and economic choice for N-alkyl amine synthesis, non-noble metal catalysts with high activity and good selectivity are rarely reported. Normally, they are severely limited due to low activity and poor generality. Herein, a simple NiCu-FeOx catalyst was designed and prepared for the N-alkylation of ammonia or amines with alcohol or primary amines. N-alkyl amines with various structures were successfully synthesized in moderate to excellent yields in the absence of organic ligands and bases. Typically, primary amines could be efficiently transformed into secondary amines and N-heterocyclic compounds, and secondary amines could be N-alkylated to synthesize tertiary amines. Note that primary and secondary amines could be produced through a one-pot reaction of ammonia and alcohols. In addition to excellent catalytic performance, the catalyst itself possesses outstanding superiority, that is, it is air and moisture stable. Moreover, the magnetic property of this catalyst makes it easily separable from the reaction mixture and it could be recovered and reused for several runs without obvious deactivation.
  • 链接地址：http://www.ionike.com/download/article/2014-04-10/168.html
  • Chlorine as an Indicator in the Controllable Preparation of Active Nano-Gold Catalyst
  • 更新时间：2014-04-10；信息类型：SCI论文
  • The controllable preparation of nano-gold catalyst maintains a challenge. Except the parameters have been revealed before, here we’d like to show that controllable preparation of active nano-gold catalyst can be achieved using chlorine as an indicator. By tracing the chlorine concentration in the washing step, a series of Au/Fe2O3 catalysts were prepared with co-precipitation method. The applying of these catalysts in CO oxidation and reductive nitrobenzene N-alkylation suggested the active catalysts were prepared from solutions containing ～2 ppm chlorine. The catalytic activity dropped dramatically if the chlorine concentration is >4–6 or <<1 ppm. Extensive characterizations revealed that the active catalyst was composed by nano-gold on the edge of Fe2O3 particle with 8.92 Au-Au coordination numbers. Although the real role of chlorine in the variation of catalyst structure and activity was still ambiguous, the current results should promote the controllable preparation of active nano-Au catalyst.
  • 链接地址：http://www.ionike.com/download/article/2014-04-10/166.html
  • Highly efficient trimerization of isobutene over silica supported chloroaluminate ionic liquid using C4 feed
  • 更新时间：2014-04-10；信息类型：SCI论文
  • A series of silica, glass and molecular sieves supported chloroaluminate ionic liquids (ILs) were prepared and their catalytic performance on the trimerization of isobutene based on C4 mixture was investigated. Interestingly, it was found that the carrier played a key role in the reaction route. Among these supported catalysts, silica supported chloroaluminate ionic liquid was highly efficient for the trimerization of isobutene. X-ray photoelectron spectroscopy (XPS) and differential scanning calorimetry (DSC) characterizations suggested that the synergy between Al2Cl7− anion and silica induced the catalytic activity for isobutene oligomerization due to the strong interaction between ILs and silanol group. The reaction conditions including loading amount, temperature, reactant concentration, and space velocity for the isobutene oligomerization were optimized. Ultimately, complete conversion of isobutene and 91.4% selectivity of trimers were obtained over the IL/silica (30 wt.%) catalyst at mild conditions. Moreover, catalyst stability and deactivation were preliminarily studied.
  • 链接地址：http://www.ionike.com/download/article/2014-04-10/161.html
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