摘要
通过对ZSM-5系列催化剂上进行N2O氧化苯制苯酚(BTOP)反应过程中反应活性和失活规律的研究,揭示了反应失活的原因,探索了减轻催化剂失活的措施,开发出了具有较高活性和稳定性的ZSM-5系列BTOP反应催化剂.实验以n(SiO2)2/n(Al2O3)=40、80、120的ZSM-5原粉(样品A、B、C)和经不同条件高温水蒸气处理的样品(A-W、B-W、C-W)为催化剂,进行了化学和XRF分析,XRD、低温N2吸附和吡啶-红外技术表征,并在催化剂装置为1 g的固定床反应器内,测定了BTOP反应活性及其下降规律.实验结果表明:在3种ZSM-5原粉中,其BTOP反应活性均随n(SiO2)/n(Al2O3)的增加有规律地降低;经高温水蒸气处理后,其初期反应活性由66%(A)～58%(B)增加到96%～98%,苯酚产率由2.35(A)～1.76(B)mmol·g-1·h-1,增加到4.00～3.16 mmol·g-1·h-1.用'L酸性中心说'对上述现象进行说明,并对水蒸气处理温度对催化剂活性的影响进行讨论,得出在本实验条件下最佳水蒸气处理温度为650～700℃.
Based on study of activation and deactivation of ZSM-5 catalysts for benzene to phenol oxidation（BTOP）, the object of the study is to detect the cause leading to deactivation of the catalysts, to find measurements decreasing deactivation rate of the catalysts and to expect to develop more active and stable ZSM-5 catalysts. The catalysts were tested in experiments including three samples of ZSM-5 in which n（SiO2）/n（Al2O3） = 40, 80 and 120 （sample A,B and C）, and the corresponding samples treated by high temperature steam（sample A-W,B-W and C-W）. These catalysts were also characterized by means of techniques of chemistry analysis, XRF, XRD, N2 adsorption in low temperature and pyridine-infrared analysis. Then the catalysts were tested in fixed-bed reactor with 1 g catalyst for their catalytic properties of activation and deactivation. The results show that for the sample A, B and C, the activation of the samples decreases with the increasing of their n（SiO2）/n（Al2O3）. At the beginning of reaction, the selectivity of phenol is only between 66%（A） ～ 58%（B） and the yield of phenol is only between 2.35（A）～1.76（B） mmol·g^-1· h^-1. But after the treatment of high temperature vapour, the selectivity and yield increase to 96%～ 98% and 4.00 ～ 3. 16 mmol·g^-1· h^-1.respectively. In the end, the effect of steam temperature on catalyst activation was also discussed. The result shows that the optium steam temperature for treating these catalysts is 650 ～ 700 ℃ under the conditions of experiments.
出处
《大连理工大学学报》
EI
CAS
CSCD
北大核心
2005年第6期802-807,共6页
Journal of Dalian University of Technology
