纳米氧化锆的制备及其在二氧化碳氧化丙烷脱氢中的应用研究
文献类型：学位论文
| 作者 | 杨玮娇 |
| 学位类别 | 硕士 |
| 答辩日期 | 2009-05-24 |
| 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 | 唐清 |
| 关键词 | 纳米ZrO2 SiO2-ZrO2复合物 丙烷脱氢 CO2吸附 |
| 其他题名 | Preparation of Nanosized Pure and Composite Zirconia Powders and its Applications in Propane Dehydrogenation by Carbon Dioxide |
| 学位专业 | 环境工程 |
| 中文摘要 | 氧化锆(ZrO2)是一种化学稳定性好、具有氧化还原性及酸碱性的催化剂载体，尤其是四方ZrO2以其优良的物理和化学性能已成为一类非常重要的催化剂载体，在丁烷异构化、N2O分解和甲烷重整中得到成功应用。近来CO2的催化转化已是温室气体减排的重要途径，其中CO2氧化丙烷脱氢反应因结合CO2的资源化和烷烃的高效活化，已引起广泛关注。纳米ZrO2兼具ZrO2和纳米材料的优异性能，应用在该反应过程已表现出较好的催化性能。但是常规方法制备的纳米ZrO2在高温下易发生晶型转变，且易团聚，无法满足CO2氧化丙烷脱氢反应对高纯稳定的四方晶型的要求。 本论文采用H2O2对溶胶凝胶法进行改性，对高纯四方ZrO2及SiO2-ZrO2复合粉末的制备进行了研究， 考察了所制备的ZrO2及复合物在CO2氧化丙烷脱氢制丙烯反应中的催化行为并进行了催化机理探讨，进一步探索了其对CO2的吸附反应性能。所取得的主要进展如下： (1) 制备出了高温稳定的纯四方相ZrO2 (12-16 nm, SBET=55.4 m2/g) 粉末及海绵状SiO2-ZrO2复合粉末。较之传统的溶胶凝胶法，H2O2改性溶胶凝胶法更有利于四方相ZrO2的形成，合适的H2O2添加量是影响ZrO2粉末均匀性和分散性的关键因素。 (2) 以纯四方ZrO2和SiO2-ZrO2为载体，采用浸渍法制备了Cr/ZrO2和Cr/SiO2-ZrO2催化剂，在CO2氧化丙烷脱氢制丙烯反应中表现出良好的催化性能。实验表明，Cr/SiO2-ZrO2催化性能优于Cr/ ZrO2， 600℃下可得到51.5%丙烷转化率和39.1%丙烯收率。SiO2的引入增加催化剂的碱性位数量，适当降低碱强度，是提高催化剂活性的原因。 (3) 论文初步探索了纳米ZrO2和SiO2-ZrO2为载体催化CO2氧化丙烷脱氢反应中的CO2吸附作用。Cr/SiO2-ZrO2比Cr/ZrO2拥有更多中等强度的碱性位，更有利于CO2与催化剂中Cr上的氧空位作用产生化学吸附，进而提高丙烷脱氢反应中的CO2转化。 |
| 英文摘要 | Zirconia (ZrO2), especially tetragonal ZrO2, is a catalyst support with excellent chemical stability, oxidation-reduction properties and acidity-alkalescence properties on its surface。It has been applied in butane isomerization, N2O decomposition and methane reforming successfully. Catalytic conversion of CO2 is one of the most important processes to utilize greenhouse gas. Propane dehydrogenation by CO2 has attracted people’s attentions, because it could expand alkenes utilization and increase CO2 conversion. For this reaction nanosized ZrO2 exhibited good catalytic performance, due to its excellent nanosized and ZrO2 properties. However, ZrO2 powders prepared by traditional processes are prone to phase transition and agglomeration at high temperature. Thus, the development of high surface and stable ZrO2 at high temperature is one of the key steps for the industrialization of this process. In order to synthesize nanosized pure and composite ZrO2 powders, appling in oxidative dehydrogenation of propane to propylene with CO2, an improved Sol-gel was used. The following achievements and innovative progresses were exhibited. (1) High percentage of tetragonal ZrO2 (12-16 nm, SBET=55.4 m2/g) and amorphous cavernous SiO2-ZrO2 powders were synthesized by improved Sol-gel method, assisted with a distillation-dehydration process after Cl- anions oxidized by H2O2. The amount of H2O2 addition was the key one to control the uniformity and dispersion of ZrO2 powders. (2) Cr/ZrO2 and Cr/SiO2-ZrO2 catalysts were prepared by impregnation of ZrO2 and SiO2-ZrO2 with chromium nitrate solution, these two catalysts exhibited good activities in dehydrogenation of propane to propylene with CO2. The propane conversion rate could reach 32.3% and 51.5%, propylene yield 25.5% and 39.1% with CO2 conversion rate of 11.3% and 16.1% over Cr/ZrO2 and Cr/SiO2-ZrO2 catalysts respectively under 600℃. It coule be attributed to lower alkaline sites and more alkaline sites by adding SiO2 that Cr/SiO2-ZrO2 showed better perdormance than Cr/ZrO2. (3) The preliminary exploration of ZrO2 and SiO2-ZrO2 applications in CO2 adsorption in propane dehydrogenation was carried out. Moderate alkaline in Cr/SiO2-ZrO2 catalyast surface benifited to CO2 chemical adsorption, as well promoted CO2 conversion in propane dehydrogenation. |
| 语种 | 中文 |
| 公开日期 | 2013-09-16 |
| 页码 | 73 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1306]  |
| 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 | 杨玮娇. 纳米氧化锆的制备及其在二氧化碳氧化丙烷脱氢中的应用研究[D]. 过程工程研究所. 中国科学院过程工程研究所. 2009. |
入库方式： OAI收割
来源：过程工程研究所
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