Pt-Pd-Rh合金的高温氧化

Oxidation of Pt-Pd-Rh Alloys at High Temperature

用ＴＧ 热重仪测定Ｐｔ－ Ｐｄ － Ｒｈ 合金的挥发失重曲线， 用Ｘ 光电子能谱（ＸＰＳ） 和溅射剥离技术确定其氧化态表层及次表层组元化学状态和浓度。结果表明合金挥发失重曲线遵循： Δｍ ＝ Ｋ０ｔｎ ———直线失重规律。合金组元化学态为Ｐｔ０ 、Ｐｄ０ 、Ｒｈ０ 、Ｒｈ２Ｏ３ ， 次表层为Ｐｔ０ 、Ｐｄ０ 、Ｒｈ０ 、ＲｈＯ２ ， Ｐｄ０ 相对富集于表层。讨论了Ｐｄ 及少量Ｒｕ 、Ｃｅ 对Ｐｔ － Ｐｄ －

The thermogravimetric analysis was used to measure the volatilization loss curves of Pt-Pd-Rh alloys.The X-ray photoelectron spectroscopy and the sputtering stripping method were used to determine the chemical state and the concentration of constituent on the surface and subsurface of Pt-Pd-Rh alloys.The results showed that:the volatilization loss of the alloys obeyed a Δm=k 0t n straight line loss law.The chemical states of constitute are Pt 0,Pd 0,Rh 0,Rh 2O 3 on the surface,and Pt 0,Pd 0,Rh 0,RhO 2 on the subsurface.Pd 0 was rich on the surface.The influence of Pd,small Ru,Ce on the volatilization loss and the surface construction of Pt-Pd-Rh alloys were discussed.