不同金属改性对Pt/β-分子筛催化柴油车尾气中HC、CO及SO_2氧化性能的影响  

Effects of metal modification on the performance of Pt/β-zeolite catalysts in the oxidation of HC,CO and SO_2 in diesel exhaust

作　　者：黄攀[1] 陈永东[1] 赖南君[1] 蒋炳正 杨草萍 张超磊[1] 陈耀强[2] 

机构地区：[1]西南石油大学化学化工学院新能源材料及技术研究中心,四川成都610500 [2]四川大学化学学院绿色化学与技术教育部重点实验室,四川成都610064

出　　处：《燃料化学学报》2016年第7期882-887,共6页Journal of Fuel Chemistry and Technology

基　　金：国家高技术研究发展计划(863计划;2013AA065304);西南石油大学启航计划项目(2014QHZ016);西南石油大学第十五期大学生课外开放实验重点项目(KSZ15064)的资助;绿色催化四川省高校重点实验室开放课题基金(LYJ1308)~~

摘　　要：采用共浸渍法制备了Ce、Cr、Mo和Cu改性的Pt/β-分子筛催化剂,运用氮吸附、XRD、H_2-TPR、NH_3-TPD和XPS等手段对该催化剂进行了表征,研究了不同金属改性对催化剂的织构性质、骨架结构、表面酸性以及在模拟柴油车尾气中抑制SO_2氧化性能和催化HC、CO氧化活性的影响。结果表明,金属改性对催化剂织构性能和骨架结构影响较小。Cr、Mo和Cu的添加可以调变催化剂酸强度,进而抑制SO_2的氧化;Cu改性的催化剂具有最好的抑制SO_2氧化的能力,在350和450℃条件下,与未改性Pt/β-分子筛催化剂相比,Cu改性催化剂上SO_2转化率分别下降了70.4%和70.2%。然而,改性金属与Pt物种之间产生的相互作用,会使Pt物种更难还原,导致Pt对HC和CO氧化的催化活性降低。Pt/β-zeolite catalysts were modified with Ce,Cr,Mo and Cu by impregnation method and characterized by nitrogen sorption,XRD,H2-TPR,NH3-TPD and XPS;the effects of metal modification on the textural properties,skeletal structure,surface acidity as well as the catalytic performance in the oxidation of SO2,HC and CO in the simulated diesel exhaust gas were investigated.The results indicate that metal modification has little influence on the textural properties and skeletal structure of the Pt/β-zeolite catalyst,whereas the addition of Cu,Cr and Mo can change the acid strength and has a stronger inhibition effect on the oxidation of SO2.Especially,the Cu-modified Pt/β-zeolite catalyst exhibits the best ability to inhibit the oxidation of SO2;the SO2 conversions over Cu modified catalyst under 350 and 450℃are decreased by 70.4%and 70.2%,respectively,in comparison with those over the unmodified Pt/β-zeolite catalyst.However,because of the interaction between metal and Pt species,Pt species becomes more difficult to reduce over the metal modified Pt/β-zeolite catalysts,which may lead to a decrease of their catalytic activity in the oxidation of HC and CO.

关 键 词：金属改性 Β分子筛 柴油车 尾气净化 催化氧化 HC CO SO2 

分 类 号：O643.3[理学—物理化学]