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用γ射线辐射法制备了铂溶胶和粒径为５ｎｍ的超细铂粉，采用机械混合法和溶胶凝胶法制备了一系列不同载体的超细铂催化剂．不同载体对提高ＣＯ氧化活性的顺序为：ＭｇＯ＞γＡｌ２Ｏ３≥ＺｒＯ２＞ＴｉＯ２＞ＳｉＯ２．其中，由溶胶凝胶法制备的０１％Ｐｔ／ＳｉＯ２和０１％Ｐｔ／ＴｉＯ２的比表面积大，Ｐｔ分散度高，但活性最差．ＸＰＳ结果表明，部分表面Ｐｔ０和ＴｉＯ２作用生成了ＰｔＯ和Ｔｉ２Ｏ３，并且Ｐｔ的分散度愈高，Ｐｔ和ＴｉＯ２间的作用愈强，从而降低了ＣＯ氧化活性．而ＭｇＯ负载的超细铂样品活性明显高于常规浸渍法所制样品．ＸＰＳ结果表明，超细Ｐｔ／ＭｇＯ表面上存在大量的化学吸附氧，这可能是ＭｇＯ负载样品活性高的重要原因．
The platinum sol and the ultrafine platinum powder with the size of 5nm were prepared by γ-ray irradiation. A series of ultrafine platinum catalysts with different carriers were prepared by mechanical mixing and sol-gel method. The order of improving the CO oxidation activity of different carriers is: MgO> γAl2O3≥ZrO2> TiO2> SiO2. Among them, 01% Pt / SiO2 and 01% Pt / TiO2 prepared by sol-gel method have large specific surface area and high Pt dispersion but their activity is the worst. The results of XPS showed that PtO and Ti2O3 were partially formed on the surface of PtO and Ti2O3, and the higher the dispersion of Pt, the stronger the interaction between Pt and TiO2, thus reducing the CO oxidation activity. The activity of MgO supported ultrafine platinum samples was significantly higher than that of the conventional impregnation method. XPS results show that a large amount of chemisorbed oxygen exists on the surface of ultrafine Pt / MgO, which may be an important reason for the high activity of MgO supported samples.