Significance of RuO2 modified SCR catalyst for elemental mercury oxidation in coal-fired flue gas.
Significance of RuO2 modified SCR catalyst for elemental mercury oxidation in coal-fired flue gas.
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DOI：
10.1021/es200223x
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发表时间：
2011-06
影响因子：
11.4
通讯作者：
N. Yan;Wanmiao Chen;Jie Chen;Zan Qu;Yongfu Guo;Shijian Yang;J. Jia
中科院分区：
文献类型：
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作者：
N. Yan;Wanmiao Chen;Jie Chen;Zan Qu;Yongfu Guo;Shijian Yang;J. Jia
将元素汞(Hg(0))催化转化为氧化态汞被认为是提高燃煤电厂汞脱除效率的有效途径。为了充分利用现有的选择性催化还原NO(X)(SCR)催化剂作为烟气中低浓度HCl转化Hg(0)的共同效益，在不同情况下考察了以二氧化钛(TiO2)为载体的各种催化剂和商品化的SCR催化剂。在所考察的催化剂中，RuO(2)催化剂本身不仅对Hg(0)的氧化表现出较高的催化活性，而且与商品化的SCR催化剂对Hg(0)的转化具有良好的协同作用。此外，添加RuO(2)的SCR催化剂表现出良好的抗SO2和氨性，对NO(X)还原和SO2转化没有明显的负面影响。在模拟气体中，即使在5ppm左右的HCl浓度下，RuO(2)掺杂的SCR催化剂对Hg(0)的氧化效率也能达到90%以上。Ru改性SCR催化剂在汞排放控制方面具有良好的应用前景。
Catalytic conversion of elemental mercury (Hg(0)) to its oxidized form has been considered as an effective way to enhance mercury removal from coal-fired power plants. In order to make good use of the existing selective catalytic reduction of NO(x) (SCR) catalysts as a cobenefit of Hg(0) conversion at lower level HCl in flue gas, various catalysts supported on titanium dioxide (TiO(2)) and commercial SCR catalysts were investigated at various cases. Among the tested catalysts, ruthenium oxides (RuO(2)) not only showed rather high catalytic activity on Hg(0) oxidation by itself, but also appeared to be well cooperative with the commercial SCR catalyst for Hg(0) conversion. In addition, the modified SCR catalyst with RuO(2) displayed an excellent tolerance to SO(2) and ammonia without any distinct negative effects on NO(x) reduction and SO(2) conversion. The demanded HCl concentration for Hg(0) oxidation can be reduced dramatically, and Hg(0) oxidation efficiency over RuO(2) doped SCR catalyst was over 90% even at about 5 ppm HCl in the simulated gases. Ru modified SCR catalyst shows a promising prospect for the cobenefit of mercury emission control.