介孔二氧化铈纳米材料的制备与性能

Preparation and Properties of Mesoporous CeO2 Nanomaterials

摘要:

采用化学沉淀法制备了纳米氧化铈（CeO2）储氧材料，利用X射线衍射（XRD）分析考察了焙烧温度对氧化铈物相结构的影响；利用热重分析(TG)对沉淀物到氧化物转变过程进行了具体分析；通过储氧量（OSC）测定和氢气程序升温还原性（H2-TPR）测定及其织构性能测定（BET法）等不同手段对CeO2材料进行了表征。结果表明：采用沉淀法制备得到的纯CeO2材料属于纳米级介孔材料。该材料具有较好的抗高温老化性能，较强的氧化还原能力，较大的比表面积和孔容及合理的平均孔径。在1000 ℃高温焙烧后仍然保持立方萤石结构，虽然有所烧结，但仍能保持纳米晶粒和纳米孔结构。

Abstract:

The nanoscale cerium (IV) oxide with oxygen-storage capacity was prepared by chemical precipitation. The influence of calcination temperature on phase structure was evaluated by X-ray diffraction. The mass change accompanied with the process of the precipitate converted to the oxide was analyzed by TG. In addition, the synthesized cerium (IV) oxide as oxygen-storage material was further characterized by OSC, H2-TPR and BET. The results suggest that the prepared cerium oxide is nano-scale mesoporous material with good tolerance of high temperature aging and good redox potential. Besides, oxygen storage and release capability loss is attributed to high calcination temperature. The synthesized material has large specific surface area and appropriate average pore size. The cubic fluorite structure and porous structure are kept perfectly even after calcination at 1000 oC.