Comparative study of MCe0.75Zr0.25Oy (M = Cu, Mn, Fe) catalysts for selective reduction of NO by CO: Activity and reaction pathways
Comparative study of MCe0.75Zr0.25Oy (M = Cu, Mn, Fe) catalysts for selective reduction of NO by CO: Activity and reaction pathways
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DOI：
10.1016/j.crcon.2021.07.002
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发表时间：
2021
影响因子：
6
通讯作者：
He Junyao-;Running Kang;Xiao-lin Wei;Junqin Huang;Feng Bin;K. Hui;K. S. Hui;Wu Dongyin-
中科院分区：
文献类型：
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作者：
He Junyao-;Running Kang;Xiao-lin Wei;Junqin Huang;Feng Bin;K. Hui;K. S. Hui;Wu Dongyin-
碱性氧炉炼钢会产生富CO的尾气。当尾气中CO和NO混合时，CO选择性催化还原(CO-SCR)有效地实现了两种污染物的协同脱除。本文制备了CuCe0.75Zr0.25Oy、MnCe0.75Zr0.25Oy和FeCe0.75Zr0.25Oy催化剂，并对它们的CO-SCR活性进行了评价，结果表明，反应体系需要厌氧，因此CO-SCR反应可以占主导地位。CuCe0.75Zr0.25Oy和FeCe0.75Zr0.25Oy的T90值分别为200℃和223℃。这两种催化剂的活性均高于MnCe0.75Zr0.25Oy(T90=0.375℃)。线状硝酸盐和桥联双齿硝酸盐是催化剂表面NO转化的主要中间物种，双齿CO_3-−配位是催化剂表面CO转化的主要中间物种。CuCe0.75Zr0.25Oy具有较高的晶格氧迁移率，更容易与NO和CO反应。在氧气存在下，大多数CO被O2氧化，CuCe0.75Zr0.25Oy、FeCe0.75Zr0.25Oy和MnCe0.75Zr0.25Oy分别持续增加到100%、100%和98%；另外，CO被O2氧化，不能进行CO-SCR反应。
Basic oxygen furnace steelmaking leads to the production of CO-rich off-gas. When CO and NO are combined in off-gas, selective catalytic reduction by CO (CO-SCR) effectively achieves the synergistic removal of both pollutants. In this paper, CuCe0.75Zr0.25Oy, MnCe0.75Zr0.25Oy, and FeCe0.75Zr0.25Oycatalysts are prepared and evaluated for their CO-SCR activity, and the results show that the reaction system needs to be anaerobic; thus, the CO-SCR reaction can be dominant. The T90values of CuCe0.75Zr0.25Oyand FeCe0.75Zr0.25Oyare 200 °C and 223 °C, respectively. The activities of these two catalysts are higher than that of MnCe0.75Zr0.25Oy(T90= 375 °C). Linear nitrate and bridged bidentate nitrate are the main intermediate species involved in NO conversion on the catalyst surface, and bidentate CO32−coordination is the main intermediate species involved in CO conversion on the catalyst surface. CuCe0.75Zr0.25Oyhas high lattice oxygen mobility and is more likely to react with NO and CO. In the presence of oxygen, most CO is oxidized by O2, which increases continuously to 100%, 100%, and 98% for CuCe0.75Zr0.25Oy, FeCe0.75Zr0.25Oy, and MnCe0.75Zr0.25Oy, respectively; additionally, CO is oxidized by O2, and the CO-SCR reaction cannot be carried out.