摘要
采用IR和XRD技术研究了B2O3/ZrO2催化剂的结构性质,用ICP-MS测定了样品中B2O3的含量,通过Hammet指示剂正丁胺滴定法测定了B2O3/ZrO2系列催化剂的表面酸性;研究了载体预处理温度对样品表面酸性和结构的影响,以及B2O3含量对样品催化性能的影响;比较了B2O3负载于ZrO2,Al2O3,SiO2,TiO2,MgO和HZSM-5上催化活性和目的产物选择性的差异。
Boron oxide catalysts supported on zirconia were prepared with B 2O 3 loading of 0 ̄20%. These materials were used as catalysts for vapor phase Beckmann rearrangement of cyclohexanone oxime (CHO) to caprolactam at 300℃. The structure of B 2O 3/ZrO 2 catalysts was characterized by means of XRD and IR. The acidity and acid strength of the samples were determined by n butylamine titration using Hammett indicators. A correlation was observed between the concentration of the surface acidic sites with intermediate strength and the selectivity for caprolactam. The feature of ZrO 2 support was realized when the catalytic performance of B 2O 3/ZrO 2 was compared with that of B 2O 3/Al 2O 3, B 2O 3/SiO 2, B 2O 3/TiO 2, B 2O 3/MgO and B 2O 3/HZSM 5. The effect of boron oxide addition was discussed.
出处
《催化学报》
CSCD
北大核心
1996年第6期512-516,共5页
关键词
氧化锆
负载型
催化剂
环己酮肟
重排反应
Boron oxide
Zirconia
Supported catalyst
Cyclohexanone oxime
Beckmann rearrangement
Caprolactam