Precise control of post-treatment significantly increases hydrothermal stability of in-situ synthesized cu-zeolites for NH3-SCR reaction
文献类型：期刊论文
| 作者 | Shan, Yulong; Du, Jinpeng ; Yu, Yunbo; Shan, Wenpo; Shi, Xiaoyan; He, Hong
|
| 刊名 | APPLIED CATALYSIS B-ENVIRONMENTAL
 |
| 出版日期 | 2020-06-05 |
| 卷号 | 266页码:1-9 |
| 关键词 | NH3-SCR Cu-zeolites Post-treatment Cu-TEPA Hydrothermal stability |
| ISSN号 | 0926-3373 |
| 英文摘要 | The origin of the beneficial effects of post-treatment processing with HNO3 and NH4NO3 solutions on the catalytic performance of copper-amine templated zeolites used in the NH3-SCR reaction was investigated. By careful design and optimization of the dual-treatment procedure (HNO3-NH4NO3), Cu-SSZ-13 catalysts were obtained using Cu-TEPA as a template that exhibited NOx conversion above 90% in a wide temperature window from 250 to 450 degrees C with GHSV of similar to 400,000 h(-1), even after hydrothermal aging at 750 and 800 degrees C. The results of XRD and H-2-TPR indicated that the HNO3 post-treatment adjusts the zeolite crystallinity and optimizes the copper species distribution in Cu-SSZ-13 catalysts. Further treatment with NH4NO3 reduces the Cu/Al ratios effectively and avoids the accumulation of Cu2+ ions to form CuOx clusters during hydrothermal aging. We investigated the influence of Cu2+ on the hydrothermal stability of Cu-SSZ-13, and two opposing effects were found. Cu2+ ions inhibit dealumination of the SSZ-13 zeolite structure, while excessive quantities of them easily accumulate to form CuOx clusters, leading to collapse of long-range order in the zeolite structure during hydrothermal aging. Before the zeolite structure collapses, Cu-SSZ-13 catalysts with high Cu loading exhibit higher NH3-SCR activity due to the preservation of more active Cu2+. However, Cu-SSZ-13 catalysts totally lose deNOx activity in NH3-SCR once the zeolite structure collapses. To guarantee both the activity for NOx reduction and hydrothermal tolerance, the optimal Cu loading (Cu/Al = 0.22 similar to 0.31, here) and structural stability of in-situ synthesized Cu-SSZ-13 should be carefully tuned by HNO3 and NH4NO3 treatment. |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/45094]  |
| 专题 | 生态环境研究中心_大气污染控制中心 |
| 推荐引用方式 GB/T 7714 | Shan, Yulong,Du, Jinpeng,Yu, Yunbo,et al. Precise control of post-treatment significantly increases hydrothermal stability of in-situ synthesized cu-zeolites for NH3-SCR reaction[J]. APPLIED CATALYSIS B-ENVIRONMENTAL,2020,266:1-9. |
| APA | Shan, Yulong,Du, Jinpeng,Yu, Yunbo,Shan, Wenpo,Shi, Xiaoyan,&He, Hong.(2020).Precise control of post-treatment significantly increases hydrothermal stability of in-situ synthesized cu-zeolites for NH3-SCR reaction.APPLIED CATALYSIS B-ENVIRONMENTAL,266,1-9. |
| MLA | Shan, Yulong,et al."Precise control of post-treatment significantly increases hydrothermal stability of in-situ synthesized cu-zeolites for NH3-SCR reaction".APPLIED CATALYSIS B-ENVIRONMENTAL 266(2020):1-9. |
入库方式： OAI收割
来源：生态环境研究中心
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