使用反气相色谱（IGC)非损伤探测技术测定二氧化铈表面脱水合和热处理

The evolution of plutonium dioxide surface due to water adsorption seems to influence H2 generation
through the radiolysis of adsorbed water. Surface evolution of ceria, a non-radioactive surrogate for plutonium
dioxide, was investigated using Inverse Gas Chromatography (IGC), Raman spectroscopy, Environmental
Scanning Electronic Microscopy (ESEM) and Atomic Force Microscopy (AFM). IGC highlights
the complexity of ceria surface revealing three different adsorption sites on surface and indicate a surface
evolution upon hydration. Thermal treatment appears to regenerate at least partially the initial surface
state before hydration. IGC points out the influence of calcination temperature of ceria precursor on surface
reactivity. The nature of surface modification was investigated by Raman spectroscopy which suggests
formation of superficial hydroxide layer. ESEM and AFM were used to study potential surface
topology modification upon superficial layer formation. Cerium hydroxide forms as a superficial layer
with a nanostructure differing from the one of the oxide.