摘要
采用晶内形成法制成Ni_xB/ZSM-5催化剂。借助XRD,H_2-TPD,XPS等技术对Ni_xB的结构和Ni_xB/ZSM-5 的表面特性分别进行了表征;并用脉冲微反色谱技术考察了催化剂的环己烷脱氢性能。结果表明,Ni_xB(P-1)是一类“渗碳体”结构的金属间充物,其结构随处理条件改变而变化。Ni_xB的特殊结构导致Ni_xB/ZSM-5表面镍原子具有较高的价不饱和性;选择适当的反应条件,Ni_xB/ZSM-5催化剂的环己烷脱氢性能较Ni/ZSM-5更好。
NixB/ZSM-5 catalysts are prepared with intracrystalline-formation method. The structure of NixB(P-1) catalyst and the surface characters of the NixB/ZSM-5 are investigated by XRD, XPS and H2-TPD techniques. By means of pulse microreactor-gas chromatographic method, the catalytic properties of the catalyst for the dehydrogenation of cyclohe-xane are tested.The results show that NixB(P-1) is a kind of cementite-like metallic compound, its structure is variable with the pretreatment conditions, the surface nickel atom of NixB/ZSM-5 catalyst shows a higher valence unsaturation.A better catalytic behavior for the dehydrogenation of cyclohexane of NixB/ZSM-5 catalyst than that of Ni/HZSM-5 is observed, when the reaction conditions are properly chosen.
