Cu-ZSM-5分子筛催化剂对NH_(3)-SCR催化性能的影响

Effect of Cu-ZSM-5 molecular sieve catalyst on catalytic performance of NH_(3)-SCR

本文以H-ZSM-5分子筛为基础,考察了制备方法、铜源类型以及铜含量对Cu-ZSM-5分子筛催化剂的NH_(3)选择性催化还原NO(NH_(3)-SCR)的性能影响。结果表明,采用离子交换法制备的Cu改性ZSM-5分子筛的NH_(3)-SCR活性最好;以Cu(NO3)2·3H2O为前驱体的Cu-ZSM-5催化剂具有最佳的低温NH_(3)-SCR催化活性,并且获得了最宽的活性温度窗口;制备所得4种不同铜含量样品中,铜含量负载为2.84%的Cu-ZSM-5分子筛催化剂的活性温度窗口范围最大,在200~600℃范围内NO转化率在90%以上。由此可以说明,引入Cu2+后能够明显提高ZSM-5分子筛的催化活性。此外,XRD分析结果显示,Cu-ZSM-5催化剂的晶相结构并未改变,SEM扫描发现分子筛的形貌并未改变,但粒径变小。本文通过考察Cu-ZSM-5分子筛催化剂的NH_(3)-SCR催化性能,为进一步制备高性能脱硝分子筛催化剂研究提供了实验依据。

Based on H-ZSM-5 molecular sieve,the effects of preparation method,copper source type and copper content on the performance of NH_(3)selective catalytic reduction of NO(NH_(3)-SCR)on Cu-ZSM-5 molecular sieve were investigated.The results showed that the Cu-modified ZSM-5 molecular sieve prepared by ion exchange method has the best NH_(3)-SCR activity;the Cu-ZSM-5 catalyst with copper nitrate as the precursor has the best low-temperature NH_(3)-SCR catalytic activity and the widest activity temperature range was obtained,Among the four samples with different copper contents prepared,the Cu-ZSM-5 molecular sieve catalyst with a copper loading of 2.84%had the largest range of active temperature window,and the NO conversion rate above 90%in the range of 200℃to 600℃.It canbe shown that the introduction of copper ions can significantly improve the catalytic activity of ZSM-5 molecular sieves.In addition,the XRD analysis results showed that the crystal phase structure of the Cu-ZSM-5 catalyst did not change,and the SEM scanning revealed that the morphology of the molecular sieve did not change,but the particle size became smaller.In this paper,the NH_(3)-SCR catalytic performance of Cu-ZSM-5 molecular sieve catalyst was investigated to provide experimental basis for further preparation of high-performance denitration molecular sieve catalyst.