Comparison of titania nanotubes and titanium dioxide as supports of low-temperature selective catalytic reduction catalysts under sulfur dioxide poisoning
Comparison of titania nanotubes and titanium dioxide as supports of low-temperature selective catalytic reduction catalysts under sulfur dioxide poisoning
复制标题
DOI：
10.1080/10962247.2016.1231144
复制
发表时间：
2017-03
影响因子：
2.7
通讯作者：
Tsungyu Lee;Sihyu Liou;H. Bai
中科院分区：
文献类型：
--
作者：
Tsungyu Lee;Sihyu Liou;H. Bai
摘要研究了一系列以TiO 2和钛纳米管为载体的铁锰氧化物催化剂在SO2存在下低温选择性催化还原NO的反应。结果表明，比表面积与B酸中心数量呈高度正相关。MnFe-TNT催化剂在SO2中毒后仍能保持较高的Mn 4 +/Mn 3+比值和比表面积，这可能是MnFe-TNT催化剂在SO2中毒后仍能保持较高性能的主要原因。通过降低空速、提高反应温度或提高[NH3]/[NO]摩尔比，可以降低SO2中毒效应。结果还表明，与金属硫酸盐的形成相比，硫酸铵的形成对NO转化效率具有更强的影响。因此，当SO2中毒是一个令人担忧的问题时，在230 oC以上运行低温SCR以避免硫酸铵的形成将是优先选择。含义：低温选择性催化还原（SCR）由于其可以降低钢铁厂和玻璃制造厂等行业中采用的SCR过程的能耗而引起越来越多的关注。然而，它也遭受二氧化硫（SO2）中毒问题。本研究探讨以二氧化钛奈米管（TiO 2 Nanotubes，TNTs）为载体的锰/铁氧化物低温选择性催化还原（SCR）催化剂，以降低SO2中毒的可能性。结果表明，MnFe-TNT催化剂比MnFe-TiO 2催化剂具有更长的耐SO2能力。
ABSTRACT A series of iron–manganese oxide catalysts supported on TiO2 and titanium nanotubes (TNTs) were studied for low temperature selective catalytic reduction (SCR) of NO with NH3 in the presence of SO2. The results showed that the specific surface area and the amount of Brønsted acid sites were highly correlated. The results also demonstrated that higher Mn4+/Mn3+ ratios and larger specific surface areas might be the main reasons for the excellent performance of MnFe-TNTs catalyst after SO2 poisoning. The SO2 poisoning effect could be minimized by reducing the GHSV, increasing the reaction temperature, or increasing the [NH3]/[NO] molar ratio. The results also indicated that the formation of ammonium sulfate had a stronger effect on the NO conversion efficiency as compared to the formation of metal sulfate. Thus operating the low temperature SCR at above 230 oC to avoid the formation of ammonium sulfate would be the priority choice when SO2 poisoning is a concerned issue. Implications: Low-temperature selective catalytic reduction (SCR) has attracted increasing attention due to that it can reduce the energy consumption for the SCR process employed in industries such as steel plants and glass manufacturing plants. However, it also suffers from the sulfur dioxide (SO2) poisoning problem. This study investigates the possibility of using titania nanotubes (TNTs) as the support of Mn/Fe bimetal oxide catalysts for low-temperature SCR to reduce the SO2 poisoning. The results indicated that the MnFe-TNT catalyst can tolerate SO2 for a longer time as compared with the MnFe-TiO2 catalyst.