| 环己酮肟气相Beckmann重排反应B2O3/TiO2-ZrO2催化剂的失活与再生 |
| Deactivation and Regeneration of B2O3/TiO2-ZrO2 Catalyst for Vapor-Phase Beckmann Rearrangement of Cyclohexanone Oxime |
|
| 摘要: 对环己酮肟气相Beckmann重排反应制己内酰胺B2O3/TiO2-ZrO2催化剂的失活原因和再生方法进行了研究。通过对失活催化剂进行N2吸附、XRD、NH3-TPD等表征后发现，引起催化剂失活的主要原因是催化剂表面因积炭所引起的酸性改变。失活催化剂在600℃于空气气氛中焙烧8h可完全恢复到新鲜催化剂的水平。 |
| 关键词: 环己酮肟 Beckmann重排反应 B2O3/TiO2-ZrO2 失活与再生 |
| 基金项目: |
| Abstract: The deactivation and regeneration of B2O3/TiO2-ZrO2 catalyst for the vapor-phase Beckmann rearrangement of cyclohexanone oxime to ε-caprolactam were studied by using adsorption of nitrogen， X-ray powder diffraction and temperature-programmed desorption of ammonia (NH3-TPD) techniques. The results indicated that the crystal structure， BET surface area and pore size distribution of the catalyst were retained after reaction. A comparison of the ammonia TPD profiles of the fresh and the used catalysts revealed a significant decrease in the number of acid sites， while the fraction of intermediate strength acids which were characterized by desorption of adsorbed ammonia between 200℃ and 300℃ changed scarcely. There was a direct relationship between the amount of coke which was formed on the catalyst and the decline in catalytic activity. These results suggested that the most possible reason for the catalyst deactivation is the coke deposition on the surface of catalyst， which leads to the coverage of the active sites. The catalyst deactivation could not attributed to the conversion of water soluble boron to water insoluble boron species. The catalytic activity can be recovered after calcining the deactivated catalyst in air at 600℃ for eight hours. |
| Keywords: cyclohexanone oxime Beckmann rearrangement B2O3/TiO2-ZrO2 deactivation and regeneration |
| |
| 摘要点击次数: 1542 |
| 全文下载次数: 1648 |
| 毛东森,卢冠忠,陈庆龄.环己酮肟气相Beckmann重排反应B2O3/TiO2-ZrO2催化剂的失活与再生[J].无机化学学报,2003,19(4):381-386. |
| 查看全文 查看/发表评论 下载PDF阅读器 |
| Support information: |
|
|
|
|
|
|
