摘要
采用热重分析仪(TG)和差热分析仪(DSC)测定海绵Pd试样从室温直至1200℃升温过程中的相对热量和质量变化;采用X射线光电子能谱(XPS)测定不同处理条件下Pd片材试样的表面状态。在吸热-放热曲线上观测到了PdO形成(260℃)、分解(720℃)和蒸发(877℃)等热效应。750℃以下Pd氧化是一个增重过程,而在更高温度下PdO的分解和蒸发导致失重。当Pd在高于850℃以上加热或淬火时,Pd呈Pd0化学态而保持光亮的金属表面;但是在低于此温度加热或淬火时,Pd表面因被PdO膜覆盖而呈暗晦色。
Changes of the relative mass and heat absorption-heat evolution of palladium were measured by TG and DSC in a temperature rising process from room temperature to 1200 ℃.The surface chemical species of palladium samples with different treatment systems were determined by XPS.For sponge palladium,a series of thermal effects,such as the formation,decomposition and evaporation of PdO at 260,720 and 877 ℃,respectively were observed on the heat absorption-heat evolution curves.The oxidation of palladium is a mass-gain process below 750 ℃,and the decomposition and evaporation of PdO lead to mass loss at temperatures above 750 ℃.When heated or quenched above 850 ℃,Pd presents Pdo state and keep a bright metallic surface;while heated or quenched below 850 ℃,Pd is coated by PdO and thus exhibits a dull color.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2011年第7期1256-1259,共4页
Rare Metal Materials and Engineering
关键词
PD
氧化
分解
蒸发
表面状态
Pd
oxidation
decomposition
evaporation
surface chemical species
