纳米CeO_2粉体的单室电沉积法制备与表征

Preparation and Characterization of Nanometer Scale Ceria by Electrochemical Deposition Method in Single Chamber Cell

单室电解槽内控制恒定的电流密度电解CeCl3溶液,最终铈盐溶液氧化水解生成CeO2·xH2O沉淀。沉淀经高温焙烧后,TEM和XRD测试表明：粒子基本呈球形,晶体粒径约为20-50 nm,为立方晶系CeO2,随着焙烧温度由500℃升高到650℃,粒子粒径逐渐增大。电解CeCl3溶液产生的氯气提供强氧化性氛围,有利于Ce^3＋氧化为Ce^4＋,从而提高了氯气氧化机制,并对其进行了初步探讨。同时,引入了电极-溶液界面区及电化学反应模型,有助于理解反应过程。

Cerium（ Ⅲ ） chloride solution was electrolyzed in a single chamber cell, with constant current density. CeO2 · xH2O deposit was obtained after the hydrolyzing and oxidizing of cerium （Ⅲ） chloride solution. The deposit was analyzed by means of TEM and XRD after calcined at high temperature. It was shown that the ceria powder was of cubic crystal group in structure and spherical in shape with the diameter of 20 - 50 nm. Furthermore, the grain size of CeO2 increased when the temperature of thermal treatment varied from 500 to 650 ℃. In the strong oxidizing ambience with Cl2, which was produced by electrolysis of cerium （Ⅲ ） chloride, it was beneficial to the oxidation of Ce^3＋ to Ce^4＋. The mechanism of chlorine oxidation was proposed and investigated preliminarily. Meanwhile, in order to understand the reaction process, electrode-solution interfacial area and the model of electrochemical reactions were introduced.