芳香族ニトリルの接触合成反応に関する研究 (第6報)

書誌事項

タイトル別名
  • Studies on the Catalytic Synthesis of Aromatic Nitriles (Part 6)
  • Ammoxidation Reaction of Various Aromatic Compounds Using Oxygen and Halogens as Oxidizing Agents
  • 酸化剤として酸素およびハロゲンを併用するアンモ酸化反応

抄録

In order to improve the ammoxidation reaction using Br2 as reported in the previous paper, aromatic ammoxidation reactions substituted O2 for part of Br2 were investigated as follows:C6H5CH3+NH3+(3-n)Br2+n/2O2→C6H5CN+(6-2n)HBr+nH2O<br>It was found that the activity of catalyst (γ-Al2O3) was stable during by far the longer period of time and the optimum reaction temperature was higher by 50-60°C than in the case of Br2. The reaction rate equation was obtained as follows in consequence of the kinetic analysis over γ-Al2O3:<br>r=6.6×104exp(-8000/RT)P0.3toluene P0.3NH<sub>3</sub> P0.5Br<sub>2</sub> P1.5O<sub>2</sub> (at 330-375°C)<br>This reaction was promoted over γ-Al2O3 and silica-alumina, but silica and diatomaceous earth were less active. The reaction wes improved remarkably over γ-Al2O3 -Cu and γ-Al2O3 -Fe, so-called Deacon's type catalyst; the ratio of Br2 to toluene could be less than 0.05, where bromine functioned as a catalyst for hydrogen abstraction.<br>The activity of the Deacon's type catalyst depended on calcining of γ-Al2O3 and a ratio of CuBr2 to γ-Al2O3, and the maximum activities were obtained Ca. 800°C of the calcination temperature and in Ca. 4 wt% of CuBr2/γ-Al2O3 ratio respectively. In the case of this reaction, the temperature and the contact time were very critical for the conversion and the selectivity. The maximum one-pass conversion of 40% to benzonitrile was obtained in Ca. 4sec of the contact time at 350°C and the maximum selectivity of 90% to benzonitrile was done in Ca. 3sec of that at Ca. 300°C. Also I2 and Cl2 as well as Br2 catalyzed formation of benzonitrile at by far the higher temperature than the case of Br2 and bromine containing compounds i.e. bromoform and benzylbromide catalyzed that too.<br>The reaction of ethylbenzene formed styrene, benzonitrile and small quantity of benzylcyanide but cumene converted to α-methylstyrene, benzonitrile and no α-phenylpropionitrile.

収録刊行物

  • 石油学会誌

    石油学会誌 18 (3), 179-186, 1975

    公益社団法人 石油学会

詳細情報 詳細情報について

問題の指摘

ページトップへ