| 两步沉淀法制备耐高温和优异还原性能CeO2材料(英文) | |
| A Two-Step Precipitation Route to CeO2 Material with Improved Thermal Stability and Reduction Property | |
| 摘要: 分别采用两种沉淀方法制备了CeO2：以传统的氨水为沉淀剂，在氨水沉淀法前引入碳铵沉淀步骤(两步沉淀法)。采用热重-差热(TG-DTA)、傅里叶变换红外(FTIR)、X光电子能谱(XPS)等手段对沉淀及其分解过程进行了研究。结果表明，在两步沉淀法中的第一步，碳酸物种为主要沉淀物种，而在第二步中被氢氧根取代。X射线衍射(XRD)和透射电子显微镜(TEM)结果表明，两步沉淀法生成的沉淀颗粒粒径更大。通过两步沉淀法制备的CeO2与氨水沉淀相比具有更好的抗高温老化性能和还原性能。经过900 ℃焙烧3 h后，仍然具有25 m2·g-1和0.11 cm3·g-1的比表面和孔容。 | |
| 关键词: 两步沉淀法 传统沉淀法 耐高温 氧化还原性能 | |
| 基金项目: | |
| Abstract: Two series of CeO2 samples were prepared by two different synthetic routes: one was conventional precipitation route employing ammonia as reactant, and the other was a two-step precipitation procedure, using ammonium carbonate ((NH4)2CO3) as precipitant at the first step and ammonia as reagent at the second step. The precipitates and their decomposition processes were characterized by thermogravimetric and differential thermal analysis (TG/DTA), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectra (XPS). The results show that the precipitate produced at the (NH)4CO3 precipitation step mainly consists of carbonate species, however, after the second precipitation step by ammonia, the carbonate species are replaced by hydroxyl species. By introducing the intermediate carbonate precipitation process, the nucleation rate of CeO2 can be controlled. X-ray diffraction (XRD) and transmission electron microscopy (TEM) results indicate that the grain size of the precipitate prepared by two-precipitation route is larger than that of the precipitate prepared by conventional route. CeO2 prepared by this two-precipitation route exhibits higher thermal stability and better reduction property than that obtained by traditional procedure. After the heat treatment at 900 ℃ for 3 h, the surface area and pore volume are 25 m2·g-1 and 0.11 cm·g-1, respectively. | |
| Keywords: two-step precipitation conventional precipitation high thermal stability redox properties | |
| 摘要点击次数: 1336 | |
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| 陈山虎,闫朝阳,曹 毅,兰 丽,赵 明,龚茂初,陈耀强.两步沉淀法制备耐高温和优异还原性能CeO2材料(英文)[J].无机化学学报,2012,28(5):1001-1008. | |
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