苯选择加氢制环己烯Ru-Fe/ZrO_2催化剂的表征

Characterization of Ru-Fe/ZrO_2 Catalyst for Hydrogenation of Benzene to Cyclohexene

采用沉淀法制备了Ru-Fe/ZrO2催化剂,通过X射线光电子能谱、BET比表面积测试法、H2程序升温还原和H2程序升温脱附等方法对其进行了表征。研究结果表明:催化剂表面的Ru物种以元素态形式存在,催化剂中有Fe2O3形式存在。Fe的引入,使催化剂平均孔径增大,比表面积明显减小,Ru-Fe/ZrO2催化剂不但吸附了更多氢气,且更有利于环己烯的脱附,从而有效地提高了选择性。在苯液相加氢制备环己烯的反应中,反应20 min时苯转化率为75.64%,环己烯的选择性为55.87%。

The Ru-Fe /ZrO2catalyst was prepared by the precipitation method and characterized by means of Xray photoelectron spectroscopy( XPS),Brunauer-Emmett-Teller specific surfacearea( BET),H2 temperatureprogrammed reduction(H2-TPR) and H2temperature-programmed desorption(H2-TPD). The results show that ruthenium exists in elemental state on the catalyst surface and a large part of the Fe are presented in the form of Fe2O3. It is found that the average pore diameter of the catalyst increases and the surface area decreases when the suitable Fe content is introduced,which is beneficial to the adsorption of hydrogenation and the desorption of cyclohexene and can improve the selectivity of cyclohexene. In liquid phase benzene hydrogenation,Ru-Fe /ZrO2catalyst exhibites higher cyclohexene selectivity. The selectivity for cyclohexene reaches 55. 87% and benzene conversion is 75. 64% at 20 min.