Reaction-driven Ion Exchange of Copper into Zeolite SSZ-13
Reaction-driven Ion Exchange of Copper into Zeolite SSZ-13
复制标题
DOI：
10.1021/acscatal.5b01200
复制
发表时间：
2015-10-01
期刊：
影响因子：
12.9
通讯作者：
Harelind, H.
中科院分区：
文献类型：
--
作者：
Clemens, A. K. S.;Shishkin, A.;Harelind, H.
我们使用了几种技术来表征暴露在与NH3-SCR还原NO相关的反应条件前后的Cu-SSZ-13，以解决观察到的NH3-SCR活性随投产时间的增加而增加的问题。具体地说，我们重点研究了用固态离子交换(SSIE)制备的样品中铜的种类，这些样品的铜负载量从0.7到5.2wt%不等。X-射线衍射表明，在反应条件下，沸石微晶表面可能残留的CuO物种明显减少。高分辨X射线衍射仪(HR-XRD)进一步揭示了Cu2O物种的相应增加。X-射线光电子能谱、俄歇电子能谱和紫外可见光谱表明，沸石孔内的铜(II)和铜(I)物种都增加了，而HR-X射线衍射仪显示，沸石结构的长程有序性得到了保留。
We have used several techniques to characterize Cu-SSZ-13 before and after exposure to reaction conditions relevant for NO reduction by NH3-SCR to address the increase in NH3-SCR activity observed as a function of time on stream. Specifically, we focus on characterizing copper species in samples prepared with solid state ion exchange (SSIE) having varying Cu loadings from 0.7 to 5.2 wt %. X-ray diffraction shows that CuO species that likely remain from the SSIE synthesis on the outside of the zeolite crystallites are significantly reduced by exposure to reaction conditions. High-resolution X-ray diffraction (HR-XRD) further reveals a corresponding increase of Cu2O species. X-ray photoelectron, Auger electron, and ultraviolet -visible spectroscopy show an increase in both Cu(II) and Cu(I) species inside the zeolite pores, with a preserved long-range order of the zeolite structure as revealed by HR-XRD.