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将离子交换法制备并经水热处理的 FeZSM-5分子筛应用于 N_2O 一步氧化苯制苯酚反应中。在固定床反应器上研究了导致催化剂失活的原因,考察了失活催化剂的再生条件,并采用热重-差热综合热分析法(TG-DTA)、N_2吸附比表面测定法(BET)和程序升温氧化法(TPO)等对失活前后的催化剂进行了表征。结果表明,FeZSM-5分子筛催化剂在 N_2O 一步氧化苯制苯酚反应中具有较高的初始活性,但失活较快。失活催化剂上存在两种形式的积炭,C 与 H 比不同的低温炭和高温炭是催化剂失活的主要原因。再生实验结果表明,失活催化剂在450℃下,在 N_2O 气氛中烧炭再生处理40 min 后,催化剂的活性可完全恢复,此时催化剂表面的积炭率仍保持在30%左右。
The FeZSM-5 molecular sieve prepared by ion exchange method and hydrothermally treated is used in the reaction of N 2 O with one-step oxidation of benzene to phenol. The reason of catalyst deactivation was investigated in a fixed bed reactor. The regeneration conditions of the deactivated catalyst were investigated. TG-DTA, BET, And temperature programmed oxidation (TPO) were used to characterize the catalysts before and after deactivation. The results showed that the FeZSM-5 zeolite catalyst had higher initial activity in the reaction of N_2O with one-step oxidation of benzene to phenol, but the deactivation was faster. There are two types of carbon deposits on the deactivated catalyst, and the low temperature charcoal and high temperature charcoal with different C and H ratios are the main reasons for catalyst deactivation. The results of the regeneration experiment show that the catalyst activity can be completely restored after the catalyst is deactivated at 450 ℃ for 40 min in a N 2 O atmosphere. At this time, the coke deposition rate on the catalyst surface remains at about 30%.