串联双釜连续反应装置中Ru-Co-B/ZrO2上苯选择加氢制环己烯

采用化学还原法制备了苯选择加氢制环己烯催化剂Ru-B/ZrO₂,考察了Cr,Mn,Fe,Co,Ni,Cu和Zn等过渡金属的添加对Ru-B/ZrO₂催化剂性能的影响.结果表明,这些过渡金属的添加均可提高Ru-B/ZrO₂催化剂中的B含量.B的修饰及第二种金属或金属氧化物的集团效应和配位效应导致Ru-B/ZrO₂催化剂活性降低和环己烯选择性升高.当Co/Ru原子比为0.06时,Ru-Co-B/ZrO₂催化剂上反应25min苯转化率为75.8%时,环己烯选择性和收率分别为82.8%和62.8%.在双釜串联连续反应器中和优化反应条件下,Ru-Co-B/ZrO₂催化剂使用419h内苯转化率稳定在40%左右,环己烯选择性和收率分别稳定在73%和30%左右.

Selective hydrogenation of benzene to cyclohexene in continuous reaction device with two reaction reactors in serie over Ru-Co-B/ZrO2 catalysts

A Ru-B/ZrO₂ catalyst for selective hydrogenation of benzene to cyclohexene was prepared using a chemical reduction method. The effects of transition metals such as Cr, Mn, Fe, Co, Ni, Cu, and Zn on the performance of the Ru-B/ZrO₂ catalyst were investigated. It was found that the addition of these transition metals all increased the B content of the Ru-B/ZrO₂ catalyst. The modification of B, the ensemble effect, and the ligand effect of the second metal or metal oxide resulted in a decrease in the activity and an increase in the selectivity for cyclohexene of the Ru-B/ZrO₂ catalyst. When the atomic ratio of Co/Ru was 0.06, the Ru-Co-B/ZrO₂ catalyst gave a selectivity for cyclohexene of 82.8% and a cyclohexene yield of 62.8% at a benzene conversion of 75.8% at 25 min. Moreover, the benzene conversion was stable at around 40%, and the selectivity for cyclohexene and the cyclohexene yields stabilized at around 73% and 30%, respectively, in 419 h under the optimum reaction conditions in a continuous device with two reactors in series.