氧化共沉淀法制备Ce0.65Zr0.25Y0.1O1.95的结构转化过程

以氨水和碳酸铵为沉淀剂, 采用氧化-共沉淀法制备了Ce0.65Zr0.25Y0.1O1.95复合氧化物, 并对不同处理温度下制备的样品用热重-差示扫描分析(TG-DSC)、傅里叶变换红外(FT-IR)光谱、X射线衍射(XRD)和表面分析仪(BET)等进行了表征. 结果表明, 共沉淀法得到的沉淀物同时含有羟基和羧基, 随着焙烧温度的升高, 分别在100-170 ℃、250-300 ℃和420-500 ℃温度范围内先后发生脱水、脱羟基和脱羧基反应, 在此过程中固溶体逐渐形成. 提出了由沉淀物转变为Ce0.65Zr0.25Y0.1O1.95复合氧化物的结构转变模型.

Structure Evolution Process of Ce0.65Zr0.25Y0.1O1.95 Prepared by Oxidation-Coprecipitation Method

Ce0.65Zr0.25Y0.1O1.95 oxides were prepared by oxidation-coprecipitation method using ammonia and salvolatile as precipitators. The as-prepared samples were thermally treated at different temperatures and characterized by thermogravimetry-differential scanning calorimetry (TG-DSC), Fourier transform-infrared (FT-IR) spectrometry, X-ray diffraction (XRD), and specific surface area measurements (BET). The results showed that the hydroxyl and carboxyl groups coexisted in the precipitate and a perfect solid solution was gradually formed with an increase in calcination temperature. The physisorbed water was lost from 100 to 170 ℃, hydroxyl groups were removed from 250 to 300 ℃, and the carboxyl groups were eliminated from420 to 500 ℃. A structure model was further proposed to understand the Ce0.65Zr0.25Y0.1O1.95 structure evolution process in depth.