钯铑比例对贵金属稀土复合物性能的影响  

Influence of Pd and Rh Ratio on the Properties of Composites of Precious Metals and Rare Earths

作　　者：张永[1] 张爱敏[1] 唐振艳[1] 贺小昆[1] 赵云昆[1] 杨冬霞[1] 郭律[1] 

机构地区：[1]昆明贵金属研究所昆明贵研催化剂有限责任公司,云南昆明650106

出　　处：《贵金属》2009年第2期26-32,共7页Precious Metals

基　　金：国家高技术研究发展计划(863项目)(2006AA03Z462)

摘　　要：通过溶胶凝胶法以无机盐为原料制备不同钯铑比例的贵金属稀土复合物,并采用透射电镜(TEM)、低温氮吸附和程序升温H2还原(TPR-H2),对其形貌特征和物化性能进行研究。结果表明:复合物以不规则球形粒子聚集成团存在,平均粒径约为100nm;其比表面积和总孔容相对偏小,前者随钯铑比例降低先减少后增加,后者呈双峰或多峰分布特征;其储氧值和还原起点温度范围分别是892.0～1535.8μmol/g和100～111℃,前者随钯铑比例降低逐渐减少,后者随钯铑比例降低先升高后降低。复合物具有作为汽车尾气净化三元催化剂涂层料的潜在优异起燃性能和储氧特性。Composites of rare earths and precious metals with different Pd and Rh ratios were prepared with inorganic materials by sol -gel method. Their morphologies and physicochemical properties were investigated through TEM, low temperature nitrogen adsorption and TPR - H2. The composites exist in a form of agglomerate of irregular sphere particles with an average particle size of 100 nm. Their specific area and total pore volume are relatively small with a bi - peak or multi - peak distribution characteristic of pore volume. The specific area firstly decreases and then increases with the decrease of Pd and Rh ratio. The oxygen storage capacity （OSC） and initial reduction temperature （IRT） range from 892.0 - 1535.8 μmol/g and 100 - 111 ℃, respectively. The former decreases with the decrease of Pd and Rh ratio, and the latter firstly increases and then decreases with the decrease of this ratio. These composites are potential washcoat materials of three - way catalysts used for automotive exhaust purification with an excellent OSC and light - off characteristics.

关 键 词：物理化学 贵金属 稀土 复合物 

分 类 号：O614.82[理学—无机化学]