单液滴CeCl_(3)溶液直接制备氧化铈的反应动力学研究

Study on Reaction Kinetics of Direct Preparation of Cerium Oxide by Single Droplet CeCl_(3) Solution

通过以100℃/s升温速率的快速热重实验模拟雾化热解过程微液滴升温过程,在全氧条件下对单液滴氯化铈溶液直接制备氧化铈的反应机理进行研究发现,对微小液滴(2μL、5μL、10μL)快速升温反应机理与传统脱水结晶反应机理完全不同。从TG曲线分析发现不同液滴的大小,脱去一部分自由水后,一步反应直接得到氧化铈,利用Arrherius方程与分解速率公式对其化学反应动力学进行研究,发现化学反应速率随液滴的直径变大逐渐变慢。反应产物能谱分析和SEM分析表明微液滴快速升温条件下能制备出高纯度氧化铈颗粒,且液滴在(2μL)以下可制备出球形颗粒。研究结果可以对稀土氯化物溶液直接制备氧化铈短流程开发提供参考。

Micro-droplet heating process in atomization pyrolysis process was simulated by rapid thermogravimetric experiment at a heating rate of 100 ℃/s. The reaction mechanism of direct preparation of cerium oxide in a single droplet of cerium chloride solution under all-oxygen conditions was studied.The mechanism of rapid temperature rise reaction of tiny droplets(2 μL, 5 μL, 10 μL) is completely different from that of traditional dehydration crystallization.From the TG curve analysis, the size of different droplets was found. After removing a part of free water, cerium oxide was obtained through one step reaction. The chemical reaction kinetics was studied by using the Arrherius equation and the decomposition rate formula. It was found that the chemical reaction rate became slower as the diameter of the droplet became larger. In this study, energy analysis and SEM analysis of the reaction products were carried out.It was found that high-purity cerium oxide particles can be prepared under rapid temperature rise of the micro-droplets, and spherical particles can be prepared below(2 μL). The research results provide reference for the short process development of direct preparation of cerium oxide from rare earth chloride solution.