Fan Yunzhao, Wang Zizi, Xin Ying, Li Qian, Zhang Zhaoliang, Wang Yingxia
School of Chemistry and Chemical Engineering, University of Jinan, Jinan, P. R. China.
State Key Laboratory for Rare Earth Materials Chemistry and Applications, Peking University, Beijing, P. R. China.
PLoS One. 2014 Feb 7;9(2):e88236. doi: 10.1371/journal.pone.0088236. eCollection 2014.
Pr and Nd co-doped Ce-Zr oxide solid solutions (CZPN) were prepared using co-precipitation and microemulsion methods. It is found that only using supercritical CO(2) drying can result in a significant improvement of specific surface area and oxygen storage capacity at lower temperatures for CZPN after aging at 1000°C for 12 h in comparison with those using conventional air drying and even supercritical ethanol drying. Furthermore, the cubic structure was obtained in spite of the fact that the atomic ratio of Ce/(Ce+Zr+Pr+Nd) is as low as 29%. The high thermal stability can be attributed to the loosely aggregated morphology and the resultant Ce enrichment on the nanoparticle surface, which are caused by supercritical CO(2) drying due to the elimination of surface tension effects on the gas-liquid interface.
采用共沉淀法和微乳液法制备了镨（Pr）和钕（Nd）共掺杂的铈锆氧化物固溶体（CZPN）。研究发现，与传统空气干燥甚至超临界乙醇干燥相比，仅使用超临界CO₂干燥可使CZPN在1000°C下老化12 h后，在较低温度下比表面积和储氧能力得到显著提高。此外，尽管Ce/(Ce+Zr+Pr+Nd)的原子比低至29%，仍获得了立方结构。高热稳定性可归因于超临界CO₂干燥消除了气液界面上的表面张力效应，从而形成了松散聚集的形态以及纳米颗粒表面的铈富集。
