ZnCl_2/C气固催化氯化吡啶制备2,3,5,6-四氯吡啶

Selective Gas Phase Chlorination of Pyridine to Produce 2,3,5,6-Tetrachloropyridine by ZnCl_2/C

以氯化锌为活性组分,活性炭为载体,通过气固催化氯化吡啶合成2,3,5,6-四氯吡啶。催化剂在低温下具有较高的收率,但易发生平行副反应而导致催化剂失活,高温下ZnCl2/C具有较好的稳定性,催化剂高温失活原因主要是活性组分的流失。在氯气与吡啶摩尔配比为7、空速为1400h-1、温度为420℃下,催化剂连续运行实验表明,2,3,5,6-四氯吡啶的收率大于54%,多氯吡啶的总收率稳定在91%以上。

2,3,5,6-Tetrachloropyridine was synthesized by selective gas-solid catalytic chlorination of pyridine with ZnCl2/C. The yield of 2,3,5,6-tetrachloropyridine at lower temperature was taller than at higher temperature, but the catalyst was more deactivated at lower temperature because of parallel-side reactions. At higher temperature, the catalyst deactivation was caused by the ZnCl2 component loss. The yield of 2,3,5,6-tetrachloropyridine was above 54%, and the total yield of chlorinated pyridines was above 91% at the conditions of ratio n （Cl2：pyridine） 7, space velocity 1400 h^-1, the temperature 420 ℃.