摘要
采用理论计算和实验方法研究了Ru-Zn/ZrO2催化剂上苯的部分加氢反应.在还原阶段于水相中引入Zn2+可使部分Zn以原子态进入Ru基催化剂.理论计算表明,Zn原子在Ru基催化剂中的存在同时抑制了苯和环己烯在催化剂表面的化学吸附,尤其是环己烯在整个催化剂表面的吸附处于一定钝化状态,这是环己烯选择性提高的重要原因.实验结果表明,Zn原子在催化剂中浓度的增加使得催化剂的加氢活性单调下降,而环己烯选择性则单调上升.实验和理论计算都证实了Ru基催化剂中最佳Zn含量的存在.
Partial hydrogenation of benzene over Ru-Zn/ZrO2 was investigated with the theoretical and experimental approaches.Atomic state of Zn was introduced into the Ru-based catalyst by loading ZnSO4 into the water phase during the reduction of the precursor.The DFT calculation showed that the presence of Zn atoms on the Ru-based catalyst has an unfavorable effect on the chemisorption of benzene and cyclohexene.Furthermore,the whole Zn atoms-modified catalyst surface is partly passivated for the chemisorption of cyclohexene,which is considered essential to the improvement of the cyclohexene yield on the Ru-Zn/ZrO2 catalyst.The experimental results showed that an increase in the Zn content in the Ru-based catalyst results in a monotonically decreased hydrogenation activity and an improved selectivity for cyclohexene.Both the theoretical and experimental investigation confirm the optimal Zn content in the Ru-based catalyst.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2009年第4期312-318,共7页
关键词
钌锌合金
氧化锆
密度泛函
苯
部分加氢
环己烯
Ru-Zn alloy
zirconia
density functional theory
benzene
partial hydrogenation
cyclohexene
