纳米级铬氧化物制备的绿色工艺研究
文献类型：学位论文
| 作者 | 裴振昭 |
| 学位类别 | 博士 |
| 答辩日期 | 2008-11-03 |
| 授予单位 | 中国科学院过程工程研究所 |
| 授予地点 | 过程工程研究所 |
| 导师 | 张懿 |
| 关键词 | Cr2O3 CrO2 水热法 纳米粒子 氧化法 |
| 其他题名 | Investigation on the green preparation process of nanometer sized chromium oxides |
| 学位专业 | 化学工艺 |
| 中文摘要 | 本论文在课题组前期工作的基础上，研究了水热凝胶法制备纳米Cr2O3新工艺和氧化法制备纳米CrO2新工艺，为铬氧化物在高性能催化剂、储氢材料和磁性材料等方面的应用提供了理论依据。 本论文取得的主要进展和创新点如下： 1. 提出了水热凝胶法制备纳米Cr2O3新工艺，并通过CrO3–HCHO体系和CrO3–C2H5OH体系制备出了纳米Cr2O3产品。新工艺具有以下特点：CrO3水溶液浓度可达11.11 ~ 14.29%wt；反应转化率趋于100%，大幅度削减了产品的Cr6+污染，实现了清洁生产；反应过程操作简单，工艺流程短。制备的Cr2O3纳米粒子符合企业标准。 2. 系统研究了水热凝胶法制备纳米Cr2O3新工艺的机理。本方法易于制备出纳米粒子的原因在于反应中生成的CO2气体分散在前驱体颗粒内部以及吸附在前驱体颗粒上，减弱了颗粒间的相互作用力，起到了表面活性剂的作用。 3. 提出了Cr(OH)3•1.1H2O氧化法制备纳米CrO2新工艺。制备的CrO2纳米粒子直径主要集中在55 ~ 89 nm的较窄的范围内。新工艺与水热法相比，反应时间大大缩短，反应温度和压力更低、工艺过程更简单。在最优化条件下，CrO2产率可接近100%。制备的CrO2产品满足企业标准。 4. 讨论了Cr(OH)3•1.1H2O氧化法制备纳米CrO2的机理。该工艺关键在于合适粒径的反应物、较低的反应温度和反应压力。 关键词：Cr2O3，CrO2，水热法，纳米粒子，氧化法 |
| 英文摘要 | In this thesis, on the basis of the preparatory work of the research group, one process to prepare Cr2O3 nanoparticles via hydrothermal gel synthesis and the other one to prepare CrO2 nanoparticles via oxidation process were investigated, which provided theoretical basis for the applications of chromium oxides on high performance catalysts, hydrogen storage materials and magnetic material. The main innovative progresses of the thesis are listed as follows: 1. A novel process to prepare Cr2O3 nanoparticles via hydrothermal gel synthesis was provided and nanosized Cr2O3 products were obtained by use of CrO3 – HCHO and CrO3 –C2H5OH reaction systems via this method. The new process has characteristics as follows: The concentration of CrO3 aqueous solution can be up to 11.11 ~ 14.29%. The reaction conversion tends to 100%, so the pollution of the products from hexavalent chromium is greatly decreased and the cleaner production is realized. The reaction process is characterized by simple operation and short process flow. The obtained Cr2O3 nanoparticles meet the enterprise standards. 2. The reaction mechanism of hydrothermal gel synthesis to prepare Cr2O3 nanoparticles was systematically investigated. That nanoparticles could be easily obtained via this method was due to the CO2 gas generated during the reaction. It dispersed in the granules interior of the precursor and adsorped on the granules of the precursor, which weakened the interaction force among granules. The CO2 gas acted as surfactant. 3. A novel process to prepare CrO2 nanoparticles by use of Cr(OH)3•1.1H2O via oxidation process was provided. The size distribution of the diameter of the obtained CrO2 nanoparticles was mainly in a narrow range of 55～89nm. In contrast to hydrothermal synthesis, this new process needs much shorter reaction time and its reaction temperature and pressure are lower. The process is simpler than hydrothermal synthesis. Under the optimal reaction condition, the productivity tends to 100%. The obtained products meet the enterprise standards. 4. The mechanism of the process to prepare CrO2 nanoparticles by use of Cr(OH)3•1.1H2O via oxidation process was discussed. The key to obtaining CrO2 nanoparticles via this method is due to the reactant with suitable size, lower reaction temperature and lower reaction pressure. Keywords: Cr2O3, CrO2, hydrothermal synthesis, nanoparticles, oxidation process |
| 语种 | 中文 |
| 公开日期 | 2013-09-13 |
| 页码 | 109 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1194]  |
| 专题 | 过程工程研究所_研究所（批量导入） |
| 推荐引用方式 GB/T 7714 | 裴振昭. 纳米级铬氧化物制备的绿色工艺研究[D]. 过程工程研究所. 中国科学院过程工程研究所. 2008. |
入库方式： OAI收割
来源：过程工程研究所
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