The activity and characterization of CeO2-TiO2 catalysts prepared by the sol-gel method for selective catalytic reduction of NO with NH3
The activity and characterization of CeO2-TiO2 catalysts prepared by the sol-gel method for selective catalytic reduction of NO with NH3
复制标题
溶胶-凝胶法制备的CeO2-TiO2催化剂用于NH3选择性催化还原NO的活性及表征
DOI：
10.1016/j.jhazmat.2009.09.112
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发表时间：
2010-02-15
影响因子：
13.6
通讯作者：
Cen, Kefa
中科院分区：
文献类型：
--
作者：
Gao, Xiang;Jiang, Ye;Cen, Kefa
采用溶胶-凝胶法制备了一系列Ce-Ti复合氧化物催化剂，并将其用于氨还原NO的选择性催化还原（SCR）反应。采用XRD、BET、XPS等技术对催化剂进行了表征。实验结果表明，在典型的SCR反应温度（300-400 ℃）和50，000 h（-1）的高气时空速下，最佳的Ce-Ti混合氧化物催化剂的NO转化率为98.6%，N-2选择性为100%。随着Ce负载量（CeO_2/TiO_2质量比）从0增加到0.6，NO转化率显著增加，但随着Ce负载量的增加，NO转化率下降。在Ce负载量为0.6的情况下获得最具活性的催化剂。高活性可能归因于高Ce负载量，Ce和Ti之间的强相互作用，高浓度的非晶态Ce在催化剂表面上，或化学吸附的氧或/和弱键合的氧物种的增加，由Ce 3+的存在导致添加后。同时考察了煅烧温度对产物的影响，最佳煅烧温度为500 ℃。氧的存在对NO的还原起着至关重要的作用，当氧浓度高于1%时，Ce（0.6）Ti催化剂的活性不受影响。SO_2和H_2O对Ce（0.6）Ti催化剂活性的影响与反应温度有关。(C)2009 Elsevier B. V.保留所有权利。
A series of Ce-Ti mixed-oxide catalysts were prepared by the sol-gel method for selective catalytic reduction (SCR) of NO with ammonia as reductant. These catalysts were characterized by XRD, BET, and XPS techniques. The experimental results show that the best Ce-Ti mixed-oxide catalyst yielded 98.6% NO conversion, and 100% N-2 selectivity at typical SCR reaction temperatures (300-400 degrees C) and the high gas hourly space velocity of 50,000 h(-1). As the Ce loading (the mass ratio of CeO2/TiO2) Was increased from 0 to 0.6, NO conversion increased markedly, but decreased at higher Ce loading. The most active catalyst was obtained with a Ce loading of 0.6. The high activity might be attributed to high Ce loading, strong interaction between Ce and Ti, high concentration of amorphous Ce on the catalyst surface, or the increase of chemisorbed oxygen or/and weakly bonded oxygen species, resulting from the presence of Ce3+ after Ce addition. The effect of the calcination temperature was also investigated, and the optimal calcination temperature was 500 degrees C. The presence of oxygen played an essential role in NO reduction, and the activity of the Ce(0.6)Ti catalyst was not depressed when oxygen concentration was higher than 1%. The effect of SO2 and H2O on the activity of the Ce(0.6)Ti catalyst was bound up with the reaction temperature. (C) 2009 Elsevier B.V. All rights reserved.