IN-SITU DIFFUSE-REFLECTANCE FTIR STUDY OF THE SELECTIVE CATALYTIC REDUCTION OF NO BY NH3 OVER VANADIA-TITANIA AEROGELS
IN-SITU DIFFUSE-REFLECTANCE FTIR STUDY OF THE SELECTIVE CATALYTIC REDUCTION OF NO BY NH3 OVER VANADIA-TITANIA AEROGELS
复制标题
DOI：
10.1006/jcat.1994.1109
复制
发表时间：
1994-05-01
影响因子：
7.3
通讯作者：
BAIKER, A
中科院分区：
文献类型：
--
作者：
SCHNEIDER, H;TSCHUDIN, S;BAIKER, A
在反应条件下，通过漫反射FTIR光谱和质谱联用程序升温解吸预吸附的NH3和NO，研究了在高表面积（BET bb0 180 m2 g-1）的钒-二氧化钛气凝胶上NH3 （SCR）对NO的选择性催化还原。这些催化剂的SCR活性随着钒负荷的增加而增加。这种行为反映在标准条件下达到50% NO转化率所需的温度上，其顺序为5% V2O5, 545 K；10% v2o5, 470 k；20% v2o5, 440 k。类似制备的高表面积（182 m2 g-1）二氧化钛气凝胶在该温度范围内没有显着的NO转化。在纯二氧化钛气凝胶上，在常温下吸附NH3后，主要观察到路易斯结合氨。结果表明，以1660和1414 cm-1为特征的bronsted结合氨参与了SCR反应。SCR活性与bronsted结合氨的比例相关，随着钒的负载气凝胶样品的显著增加。(C) 1994学术出版社，Inc.
Selective catalytic reduction of NO by NH3 (SCR) on high surface area (BET > 180 m2 g-1 vanadia-titania aerogels with 5, 10, and 20 wt% of vanadia, has been investigated by diffuse reflectance FTIR spectroscopy coupled with mass spectrometry under reaction conditions and by temperature-programmed desorption of preadsorbed NH3 and NO. The SCR activity of these catalysts increases with the vanadia loading. This behaviour is reflected by the temperatures necessary to reach 50% NO conversion under standard conditions, which decreased in the sequence 5% V2O5, 545 K; 10% V2O5, 470 K; 20% V2O5, 440 K. A similarly prepared high surface area (182 m2 g-1) titania aerogel does not exhibit significant NO conversion in this temperature range. On pure titania aerogel, mainly Lewis-bound ammonia is observed subsequent to NH3 adsorption at ambient temperature. In contrast, it is shown that Bronsted-bound ammonia, characterized by bands at 1660 and 1414 cm-1, is involved in the SCR reaction. The SCR activities correlate with the fraction of Bronsted-bound ammonia which significantly increases with the vanadia loading of the aerogel samples. (C) 1994 Academic Press, Inc.