| 张小明.Au/N-Ti-HMS的制备及其催化丙烯直接环氧化反应的研究[J].分子催化,2011,(3):213-219 |
| Au/N-Ti-HMS的制备及其催化丙烯直接环氧化反应的研究 |
| Preparation of Au/N-Ti-HMS and the Direct Epoxidation of Propylene Using H2 and O2 |
| 投稿时间：2011-04-10 修订日期：2011-04-18 |
| DOI： |
| 中文关键词: Ti-HMS 氮化作用 纳米金催化剂 丙烯环氧化 |
| 英文关键词:Ti-HMS Nitridation Nano-gold catalysts Propylene epoxidation |
| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| 中文摘要: |
| 以十二胺为模板剂合成了一系列不同Ti含量的介孔分子筛Ti-HMS，并通过高温氨处理对其进行高温改性，在分子筛表面和骨架中引入碱性N原子。分别以改性前后的Ti-HMS为载体使用沉积沉淀法制得纳米金催化剂，并考察氢气、氧气共存条件下催化丙烯气相直接环氧化的催化性能。通过氮气等温吸附-脱附、X射线衍射(XRD)、傅里叶变换红外(FT-IR)光谱、紫外-可见漫反射(DR UV-Vis)光谱、电感耦合等离子体原子发射光谱法(ICP-AES) 及高倍透射电镜(HRTEM)对载体及纳米金催化剂进行了表征。结果表明：合成的Ti-HMS分子筛试样具有典型的六方介孔特征， Ti以骨架四配位状态存在。以850℃高温氮化改性Ti-HMS为载体制备的纳米金催化剂，在常压、100℃条件下，催化丙烯环氧化，反应30 min后，丙烯的转化率达6.28％，环氧丙烷的选择性为83.10％；反应270min后丙烯的转化率降至4.74%，环氧丙烷的选择性为82.49％。经高温改性处理后，催化剂的活性及稳定性都得到了大幅度提高。 |
| 英文摘要: |
| Titanium-containing hexagonal mesoporous silicas(Ti-HMS) with different Ti contents have been prepared using dodecylamine as template. Nitrogen-incorporated Ti-HMS molecular sieves were preparation by NH3 at high temperature. Ti-HMS and Nitrogen-incorporated Ti-HMS supported Au catalysts were obtained by a deposition-precioitation method. The catalytic performance was evaluated by the direct gas phase epoxidation of propylene using hydrogen and oxygen. The samples were characterized by nitrogen isothermal adsorption-desorption, XRD, FT-IR, DR UV-Vis, ICP-AES and HRTEM. The results showed that Ti-HMS molecular sieves are hexagonal mesoporous in structure. Titanium species exist in tetra-coordinated state. Superior performance was obtained with the Au catalyst supported on Ti-HMS was modified by NH3 at 850℃. 6.28% of propylene conversion, and 83.10% of PO selectivity can be obtained at 373 K in the initial 30 min of time-on-stream. The propylene conversion and PO selectivity were 4.74 and 82.49％ after running 270min. The performance of the Au catalyst for propylene epoxidation was improved by N-modified of the Ti-HMS supports. |
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