Effects of NO2 Addition on the NH3-SCR over Small-Pore Cu-SSZ-13 Zeolites with Varying Cu Loadings
Effects of NO2 Addition on the NH3-SCR over Small-Pore Cu-SSZ-13 Zeolites with Varying Cu Loadings
复制标题
添加 NO2 对不同 Cu 负载量的小孔 Cu-SSZ-13 沸石上 NH3-SCR 的影响
DOI：
10.1021/acs.jpcc.8b05930
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发表时间：
2018
影响因子：
3.7
通讯作者：
He Hong
中科院分区：
文献类型：
--
作者：
Shan Yulong;Shi Xiaoyan;He Guangzhi;Liu Kuo;Yan Zidi;Yu Yunbo;He Hong
具有不同铜负载量的小孔 Cu-SSZ-13 沸石被应用于标准和 NH3 快速选择性催化还原 (SCR) NO。结果发现，铜负载量的增加有助于标准 SCR，同时抑制快速 SCR。通过比较 Cu-SSZ-13 和 H-SSZ-13 沸石上的 NO 和 NO2 转化活性，分析了快速 SCR 条件下的 NO 和 NO2 反应途径。在低温下，NO2 的添加会由于 NH4NO3 的形成而强烈抑制 NO 转化。与中孔和大孔沸石相比，小孔被形成的NH4NO3堵塞更严重，使得几何尺寸与小孔相似的反应物分子（NH3和NO2）更难通过通道开口。此外，在高温下NH4NO3分解时，由于快速SCR反应的发生，NO2对NOx转化表现出促进作用，尤其是在低Cu负载量的Cu-SSZ-13上。
Small-pore Cu–SSZ-13 zeolites with varying Cu loadings were applied in the standard and the fast selective catalytic reductions (SCR) of NO with NH3. It was found that increased Cu loadings contributed to standard SCR, while inhibited fast SCR. The NO and NO2reaction pathways were analyzed under fast SCR conditions by comparing the NO and NO2conversion activities over Cu–SSZ-13 and H–SSZ-13 zeolites. At low temperatures, NO2addition strongly inhibited the NO conversion because of the formation of NH4NO3. Compared to medium- and large-pore zeolites, the small pores were blocked more severely by the formed NH4NO3, making it more difficult for the reactant molecules (NH3and NO2) with geometric dimensions similar to those of the small pores to go through the channel opening. Additionally, at high temperatures when NH4NO3decomposed, NO2showed a promotion effect on NOxconversion because of the occurrence of the fast SCR reaction, especially on Cu–SSZ-13 with low Cu loadings.