【摘要】 针对超细氧化铈前驱体焙烧过程中所产生的团聚和烧结问题，提出了一种利用多功能网状框架聚乙二醇（PEG）制备超细氧化铈粉体的前驱体碳酸铈盐的新思路，采用TG-DSC热分析仪研究前驱体的热分解过程并进行动力学分析，考察了焙烧温度、升温速率、保温时间对超细氧化铈粒径、形貌及晶体结构的影响。实验结果表明：前驱体的热分解过程分为3个阶段：第一阶段温度为25²58℃时，为脱自由水阶段，质量损失率为2.94%；第二阶段温度为258⁴22℃时，质量损失率为11.86%，前驱体Ce（CO₃）₂O·H₂O、Ce₂（CO₃）₂O·H₂O分解为CeCO₃OH和CeO₂；第三阶段温度为422⁶30℃时，残留的PEG高温氧化分解挥发，部分稀土碳酸铈盐CeCO₃OH分解生成晶型完美的氧化铈，质量损失率为10.29%。运用Freeman-Carroll法计算确定第二阶段反应活化能（E）为166.68 kJ/mol，反应级数（n）为19.27；第三阶段反应活化能（E）为101.95 kJ/mol，反应级数（n）为14.75。确定在焙烧温度为1 000℃，升温速率为300℃/h，保温时间为3 h的焙烧制度下，可得到中值粒径D₅₀≤0.50μm的超细氧化铈粉体。更多还原

【Abstract】 Aiming at the agglomeration and sintering problems generated during the roasting process of ultrafine cerium oxide precursor,a new idea of using multifunctional reticulated framework polyethylene glycol（PEG） to prepare the precursor cerium carbonate salts of ultrafine cerium oxide powder was proposed,and the thermal decomposition process and kinetic analysis of the precursor were studied by using the TG-DSC thermal analyser and the effect of the roasting temperature,the rate of heating and the holding time on the particle size,morphology and crystal structure of the ultrafine cerium oxide were investigated.The effects of temperature,morphology and crystal structure were investigated.The experimental results showed that the thermal decomposition of the precursor was divided into three stages.The first stage at 25²58 ℃ was the stage of demineralised water,with a weight loss of 2.94%.The second stage was at 258⁴22 ℃ with a weight loss of 11.86%,and the precursors Ce（CO₃）₂O·H₂O and Ce₂（CO₃）₂O·H₂O were decomposed into CeCO₃OH and CeO₂.The third stage was at 422⁶30 ℃,the residual PEG was volatilised by high temperature oxidative decomposition,and part of the rare earth cerium carbonate salt CeCO₃OH was decomposed to produce perfectly crystalline cerium oxide with a weight loss of 10.29%.Using the Freeman-Carroll method,the activation energy（E） of the second reaction stage was determined to be 166.68 kJ/mol,and the number of reaction stages（n） was 19.27.The activation energy（E） of the third reaction stage was determined to be101.95 kJ/mol,and the number of reaction stages（n） was 14.75.It was found that under the roasting system with a roasting temperature of 1 000 ℃,a temperature rise rate of 300 ℃/h and a holding time of 3 h,the mean particle size D₅₀≤0.50 μm of the ultrafine ceria powder could be obtained.更多还原