【摘要】 采用聚合羟基复合阳离子合成交联黏土Al-Ce-PILC,经SO42-改性后,以浸渍法制备了铜基交联黏土催化剂Cu/Al-Ce-PILC,并将其应用于C3H6选择性还原NO的反应,考察了预处理气氛、O2和C3H6浓度、空速、水蒸气和SO2等反应条件对催化剂性能的影响.结果表明,He预处理后催化剂表面的Cu物种以Cu+和Cu2+两种形式存在,而H2预处理后仅以Cu+存在,NO转化率最大值由23%升至56%.反应体系中适当的O2和C3H6浓度可促进NO还原为N2,但过高的浓度反而可降低NO的还原活性,O2同时可起到抑制积炭、清洁催化剂表面的作用.NO转化率随着空速的增大而降低.10%水蒸气的存在可抑制NO的还原和C3H6的氧化,其转化率曲线向高温方向位移.但是,由于金属氧化物交联柱表面的疏水特性,Cu/Al-Ce-PILC较Cu/ZSM-5具有较强的耐湿热稳定性,NO和C3H6最大转化率仅分别下降13%和5%.SO2的存在明显抑制了催化剂的低温活性,但对高温活性有一定促进作用.更多还原

【Abstract】 Montmorillonite was pillared by multi-oligomeric hydroxyl cations to synthesize Al-Ce-PILC（PILCpillared interlayer clay）,which was modified by SO^2-₄ and then was used as a catalyst support to prepare the Cu/Al-Ce-PILC catalyst by impregnation.The influence of pretreatment atmosphere,concentration of O₂ and C₃H₆,space velocity,water vapor,and SO₂ on the conversion of NO and C₃H₆ over Cu/Al-Ce-PILC was investigated.The results showed that both Cu⁺and Cu²⁺ species were observed on Cu/Al-Ce-PILC pretreated in He,while only Cu⁺ existed after being pretreated in H₂,and the maximum NO conversion was enhanced from 23% to 56%.Proper concentration of O₂ and C₃H₆ promoted the reduction of NO to N₂,and the formation of coke was distinctly suppressed by excess oxygen.NO conversion decreased with increasing space velocity.The presence of 10% water vapor in the feed restrained the selective catalytic reduction（SCR） of NO,the temperature for the maximum conversion increased,and the maximum conversion of NO and C₃H₆ decreased by 13% and 5%,respectively.Compared with Cu-ZSM-5,Cu/Al-Ce-PILC showed better resistance to water vapor owing to the hydrophobic nature of the oxide pillar surface.SO₂ greatly inhibited the SCR activity of Cu/Al-Ce-PILC at low temperature and slightly promoted it at high temperature.更多还原