Cu/Al-PILC催化的C_3H_6选择还原NO反应的研究

Study on selective catalytic reduction of NO by propylene over Cu/Al-PILC catalysts

采用聚合羟基铝交联剂对蒙脱土进行撑柱 ,合成铝交联黏土 (Al PILC) ,并以其为载体 ,制备了应用于C3 H6选择还原NO的催化剂Cu/Al PILC。考察了制备工艺条件及La2 O3 助剂对催化剂性能的影响 ,并采用DTA、IR技术对Al PILC进行表征。研究结果表明 ,Al PILC热稳定性随Al/clay比增加逐步提高 ,SO2 -4改性Al PILC上SO2 -4与铝氧化柱形成了具有超强酸性的结构 ,催化活性得到显著提高 ;当Al/clay比为 10mmol/g ,浸渍SO2 -4量为 2 0 % (wt) ,Cu担载量为 3% (wt) ,空速2 0 0 0 0h-1时 ,Cu/Al PILC在 35 0℃NO转化率达到最大值 5 2 0 2 % ;浸渍 0 5 %La2 O3 提高了Cu/Al PILC催化剂的活性和热稳定性。

In this paper,raw montmorillnoite was pillared by oligomeric hydroxyl aluminum cation to synthesize Al pillared interlayered clay(Al-PILC). Cu/Al-PILC catalysts were prepared by changing preparation parameters and applied to selective catalytic reduction of NO by propylene in the presence of oxygen.The influence of preparation parameters and adding 0.5%La 2O 3 as promoter on catalytic properties of Cu/Al-PILC catalysts were investigated,and the structure of Al-PILC was characterized by means of DTA and IR. The results showed that the stability of Al-PILC increased with Al/clay ratio and the activity of catalyst improved greatly since superacid structure was formed while Al-PILC modified by SO 2- 4.At space velocity 20 000 h -1,the maximum conversion of NO obtained 52.02% at 350℃. The most suitable Al/clay ratio, SO 2- 4 content and Cu loading are 10 mmol/g,20%(wt) and 3%(wt) respectively.The doping of 0.5%La 2O 3 on Cu/Al-PILC increased its activity and stability.