新型苯选择加氢制环己烯非晶态催化剂Ru-Fe-B/ZrO2的制备及其可调变性

采用化学还原法制备了一种新型高活性和高选择性苯选择加氢制环己烯的Ru-Fe-B/ZrO2纳米非晶态合金催化剂,并利用透射电镜、选区电子衍射、X射线衍射和N2物理吸附仪等手段对催化剂进行了表征.重点研究了Ru-Fe-B/ZrO2催化剂活性和选择性的可调变性,及还原剂NaBH4浓度和洗涤后滤液的pH值对其催化性能的影响.结果表明,在新型Ru-Fe-B/ZrO2催化剂上,当苯转化54%时,环己烯选择性高达80%,同时环己烯选择性随苯转化率升高而缓慢下降.向反应浆液中添加酸性或碱性物质可以调变催化剂的活性和选择性,同时催化剂制备工艺和性能具有很好的可重复性.Ru-Fe-B/ZrO2催化剂融合了纳米和非晶材料的特性,这是其对苯选择加氢制环己烯表现出高活性和高选择性的主要原因.

Preparation and Modifiable Character of a Novel Amorphous Catalyst Ru-Fe-B/ZrO2 for the Selective Hydrogenation of Benzene to Cyclohexene

A novel nano-amorphous Ru-Fe-B/ZrO_2 catalyst was prepared by the chemical reduction method and showed high activity and selectivity in the selective hydrogenation of benzene to cyclohexene.The catalyst was characterized by transmission electron microscopy,selected-area electron diffraction,X-ray diffraction,and N2 adsorption.The modifiable character of the activity and selectivity of the catalyst and the effects of NaBH4 concentration and pH of the filtrate on the catalyst performance were investigated.The results showed that over this catalyst the selectivity for cyclohexene reached 80% at 54% of benzene conversion.Moreover,the selectivity decreased slowly with the increase of benzene conversion.The activity and selectivity of the catalyst could be adjusted through adding acid or alkali to the reaction system.The catalyst preparation and properties could be repeated.It was concluded that the nanometer scale and amorphous structure of the catalyst were the main factors for its high activity and selectivity for the selective hydrogenation of benzene to cyclohexene.