还原方式对Ru-Zn/ZrO_2催化剂上苯加氢反应的影响

Influence of reduction method on the Ru-Zn/ZrO_2 catalysts activity in benzene selective hydrogenation

以苯选择性加氢制环己烯为模型反应,考察了Ru-Zn/ZrO_2催化剂制备过程中还原方式对催化剂催化性能的影响.运用TEM、SEM、BET等技术对催化剂进行了表征.评价结果表明,采用高压液相还原制备的RuZn/ZrO_2-3催化剂在苯选择加氢制环己烯反应中表现出高催化性能,当苯转化率为41%时,环己烯选择性达到了83.8%.TEM、SEM结果表明催化剂上Ru微晶呈高分散,有利于苯转化率的提高.BET比表面积25 m^2/g,RuZn/ZrO_2-3催化剂最可几孔径分布范围20~50 nm,有利于环己烯选择性的提高.

The Ru-Zn/ZrO2 catalysts prepared by coprecipitation method with different reduction conditions were used for selective hydrogenation of benzene to cyclohexene. The characterization of the catalysts has been carried out by means of BET, SEM and TEM. Ru-Zn/ZrO2-3 catalyst, which was reduced with 140 ℃ and 4.0 MPa H2,the benzene conversion and cyclohexene selectivity were 41% and 83.8%,respectively.It was found that the dispersion of Ru was responsible for the high activity of Ru-Zn/ZrO2-3 catalyst.In addition ,the suitable pore size distribution of the catalyst was between 20 nm and 50 nm, which was beneficial for the increase of selectivity toward cyclohexene of the catalyst.