甲醇燃料车尾气净化催化剂的研究Ⅲ.甲醇深度氧化用Ag-Pd/γ-Al_2O_3催化剂中Ag与Pd的协同作用  

STUDY ON CATALYSTS FOR METHANOLFUELED VEHICLE EXHAUST CONTROL Ⅲ. The Synergy between Ag and Pd in AgPd/γAl_2O_3 for Methanol Deep Oxidation

作　　者：朱兵[1] 汪仁[1] 

机构地区：[1]华东理工大学工业催化研究所

出　　处：《催化学报》1997年第6期468-472,共5页

基　　金：国家教委博士点基金

摘　　要：以银氨络离子和氯钯酸铵为前驱体制备了５％Ａｇ０１％Ｐｄ／γＡｌ２Ｏ３催化剂，其低温深度氧化性能明显优于Ａｇ或Ｐｄ单组分催化剂；Ｔ５０和Ｔ９５（ＣＨ３ＯＨ）分别为１２５℃和１７０℃，且不受Ｏ２及ＣＯ的阻抑．Ｏ２ＴＰＤ的结果表明，随着在Ａｇ组分中加入Ｐｄ及Ｐｄ加入量的增加，Ｏ２的低温脱附峰（Ｔｐ＜２００℃）逐渐减弱至消失；中温脱附峰（２５０℃＜Ｔｐ＜４００℃）则向低温位移；高温脱附峰（Ｔｐ＞５００℃）峰面积逐渐增大，峰温比单组分钯的氧脱附峰高．Ｐｄ与Ａｇ的相互作用（电荷转移）是造成上述现象的原因．The deep oxidation of methanol on AgPd/γAl_2O_3 catalysts at low temperature has been investigated. The results are as follows: 5%Ag01%Pd/γAl_2O_3 which is prepared by impregnating Ag(NH_3)_2Cl and (NH_4)_2PdCl_4 precursor solution into γAl_2O_3 and calcined in reducing gas has very high methanol oxidation activity and perfect deep oxidation selectivity, its T_50 and T_95 is 125℃ and 170℃ respectively, the content of max formaldehyde formation is only 30×10-6. In addition, this catalyst isn't subject to the inhibition coming from CO and O2 in feed gas and has good thermal stability. By means of TPD technique using CO and O2 as probe molecules, the synergy between Ag and Pd in AgPd/γAl2O3 has been studied. As the amount of Pd loading increases, the oxygen desorption peak at low temperature (Tp<200℃) gradually decreases to vanish, the peak at middle temperature (250℃<Tp<400℃) moves to lower temperature. These phenomena result from the electron transfer between Ag and Pd.

关 键 词：甲醇燃料 汽车尾气净化 深度氧化 银 钯 催化剂 

分 类 号：X511.06[环境科学与工程—环境工程] O643.36[理学—物理化学]