Study on catalyst for pyridine synthesis

摘要

The synthesis of pyridine from aldehydes and ammonia was performed over ZSM-5 catalyst. The catalytic activity in reaction was correlated with the acidity of the zeolite catalysts. In this study a few of ZSM-5 (m(SiO_2)/m(Al_2O_3)= 120) were prepared and modified with Co~(2+), Fe~(3+). The surface acidity was determined by Py-IR technique. It was found that CoZSM-5 and FeZSM-5 have fewer Lewis acid sites than HZSM-5. The decrease of Lewis acid sites leads to decreasing the ability of NH_3 adsorption, this phenomenon insures that there are adequate acid sites discovering and reacting with aldehydes. It is advantageous to the reaction. By using a CoZSM-5 catalyst, the yields of pyridine base can reach 78 percent. The study provides a theoretical base for preparing high activity and high selective catalyst for pyridine synthesis.