氨氧化催化合成氰基吡嗪的研究  

Study on the Synthesis of 2-Cyanopyrazine by Catalytic Ammoxidation

作　　者：洪春[1] 李勇[1] 刘磊[1] 

机构地区：[1]浙江大学化学工程与生物工程学系,浙江杭州310027

出　　处：《高校化学工程学报》2005年第6期808-812,共5页Journal of Chemical Engineering of Chinese Universities

摘　　要：研究2-甲基吡嗪氨氧化催化合成2-氰基吡嗪的催化反应机理后,可知2-甲基吡嗪是通过一系列的脱氢、氧化生成甲醛吡嗪和羧酸吡嗪然后氰化生成产物的,因此优良的催化剂必须由活性及数目合适的脱氢、供[O]及氰化中心组成。分析了各种氨氧化催化剂后,研制了Sb2O3-V2O5-TiO2/SiO2型催化剂,通过实验分别考察反应温度,进料空速,原料配比的影响。确认在空速0.3h-1,反应温度380℃,配料比为2-甲基吡嗪:氧气:氨气=1:8.5:3(摩尔比)时,2-甲基吡嗪的转化率为70%以上,2-氰基吡嗪的收率为55%以上。与同类催化剂相比,具有反应温度低,空速大等优点,更适合工业化;同时也验证了催化反应机理的合理性。The mechanism of 2-cyanopyrazine prepared from 2-methylpyraine by catalytic ammoxidation was studied. It could be conjectured that 2-methylpyrazine is reacted via a series of dehydrogenations and oxidations to form intermediates pyrazinyl carboxylic acid and pyrazinamide which are then cynadized into 2-cyanopyrazine. During these reactions, an excellent catalyst with proper quantity and activity of supplying oxygen, dehydrogening and cyaniding is necessary. A new catalyst （Sb203-V2Os-TiO2/SiO2）was selected from a lot of ammoxidation catalysts that we had studied. Factors affecting the ammoxidation such as reaction temperature, space velocity and feed composition were investigated through experiments. It is found that the space velocity 0.3h^-1, the reaction temperature 380℃ and the ratio of 2-methylpyrazine, 02 and NH31：8.5：3 are the most suitable operating condition for the Sb22O3-V2O5-TiO2/SiOz catalyst. Compared with others, this catalyst has more advantages such as it suits with greater space velocity and lower reaction temperature, so it can be applied to industry. On the other hand, the reasonableness of the inferred mechanism of catalytic ammoxidative reaction is proved.

关 键 词：2-氰基吡嗪 2-甲基吡嗪 氨氧化 催化剂 

分 类 号：O621.256.2[理学—有机化学] TQ253.29[理学—化学]